|This article is about a/an episode in Power Rangers Operation Overdrive.|
Once a Ranger are the twentieth and twenty-first episodes of Power Rangers Operation Overdrive. They are a two-part special team-up involving Power Rangers from five different generations (collectively known as the Retro or Veteran Rangers) assisting the Overdrive Rangers in defeating a new threat: Thrax, the son of Lord Zedd and Rita Repulsa. The title of the episode is a reference to the long-standing phrase "Once a Ranger, always a Ranger." The episode also commemorates the 15th Anniversary of the Power Rangers franchise.
The son of Lord Zedd and Rita Repulsa, Thrax, unites all four Corona Aurora-seeking factions of villains into a new Evil Alliance. When they manage to overwhelm the Overdrive Rangers, their connection to the Morphing Grid is severed, and their powers destroyed! With the gems still needing protection, Sentinel Knight assembles a team of replacement Rangers, made up of members of previous (or future) teams of Power Rangers.
No longer having Ranger powers, the "former" Overdrive Rangers return to their civilian lives. All but Mack, who learns of Thrax's plans to destroy Sentinel Knight, and seeks out the only item capable of doing so, the legendary sword Excelsior. Will he be doing this alone, or can the call of action prove the adage of "Once a Ranger, Always a Ranger" to his former teammates? Meanwhile, their replacements, the team of Retro Rangers, head to Angel Grove to seek out the only being capable of repairing the Morphing Grid: Alpha 6! Even if they succeed, can two combined teams of Power Rangers stop Thrax for good, and permanently break up the Evil Alliance?
A monster walks out of a museum in San Angeles. People run in terror as Miratrix and Kamdor wait. Monster: Kamdor, I have it! The most precious gem in the museum. Kamdor: Fool! You said you could find one of the jewels of the Corona Aurora. The gem was only a ruby and Kamdor tossed it. Miratrix caught it. If Kamdor didn't want it, she would take it. The Rangers arrived and battled Miratrix, Kamdor and the monster. destroying the monster. Miratrix and Kamdor decided to retreat.
Norg goes sliding down into the ice den. Flurious is sitting on his throne. Norg lands with his head into the snow and merges with his head surrounded by ice. After Norg gets after his brain freeze, he walks over to Flurious. Norg had something by the entrance and thinks it's a present for Flurious. Flurious opens the container and a voice greets him and tells him thaf since he is an enemy of the Earth, they should meet. Back in the city, the citizens are cheering the teens. Rose promises to get the ruby back to the museum. A short distance away, Miratrix and Kamdor are watching. Kamdor is not happy, but Miratrix is happy that at least none of the others losers have any of the jewels. A container appears in Kamdor's hands. Kamdor opens it and the same voice invites them to join him, and he will help them get the jewels of the Corona Aurora. Miratrix is pleased, but Kamdor tosses the container aside. Kamdor doesn't need anyone's help. The container opens and a green glows emerges, surrounding Kamdor and Miratrix. Kamdor and Miratrix find they have been transported to a cave. Kamdor sees Flurious and thinks he is the one, but Flurious tells Kamdor he had been invited. Not only Flurious is there, but there are also Norg, Moltor, and the Fearcats. A young creature walks in and introduces himself as Thrax. Miratrix recognizes the name. Thrax had been imprisoned by Sentinel Knight. Thrax tells them, much like Moltor and Flurious, he had been imprisoned by Sentinel Knight. But evil like his could not be contained. As Sentinel Knight grew weaker, he grew stronger. Thrax was able to break free from his imprisonment, a dumpster on the moon. Thrax came to Earth. Thrax tells them enough about him. Thrax points out the one thing that has kept all of them from plundering the Earth to obtain the jewels of the Corona Aurora - the Power Rangers. Kamdor adds the Rangers are strong. Thrax tells them that is why they must work together. Flurious, Moltor, the Fearcats, Kamdor and Miratrix are outrage and refused to work together. Thrax tells them they will form an allegiance only until the Power Rangers are destroyed. With the Rangers gone, they can do what they want. Thrax has a plan, and everyone gathers around to listen. Meanwhile, the teens are back at the mansion. Rose comments that she can't remember what her life was like before becoming a Ranger. Will admits none of his adventures have beat being a Ranger. Mack comments he can remember what it was like before becoming a Ranger, boring. Tyzonn tells them they shouldn't forget why they are Rangers. The rest look at him questioning. Tyzonn tells them to save the Earth. Everyone laughs. The screen comes on and it shows Thrax, Flurious, Moltor, Kamdor, Miratrix, Fearcats, and a couple of Chillers. Thrax introduces himself as the son of Rita and Lord Zedd and promises to be the demise of the Power Rangers.
The Rangers arrive in the city via the S.H.A.R.C. and they battle Moltor, Flurious, Fearcats, Miratrix, Kamdor, Thrax. Several Chillers and Lava Lizards in the battle as well. It is a difficult battle for the Rangers, who call in the Transtek Armor, and that is not much help for the Rangers. Miratrix, Kamdor, and the Fearcats take a moment to pause and reflect that Thrax is right, it is much easier to defeat the Rangers working together. Thrax tells them they now need to combine all their evil energy together. They all do so, including Moltor and Flurious. The wave of evil energy reaches the universal morphing grid and does a lot of damage to it. The Rangers are surprised when they are demorphed. Thrax tells the teens what has happened. Before Thrax and the rest can destroy the Rangers, Sentinel Knight appears to protect them. Sentinel Knight uses his power to take the teens to safety. Thrax isn't worried as now the Earth and the jewels are theirs for the taking. After Sentinel Knight deposits the teens to safety he vanishes. The teens are upset as they realize they no longer have Ranger powers. The teens manage to get to the control center. Mr. Hartford is at a loss on how to repair the morphing grid. The teens are trying to repair their Trackers and are upset. Spencer walks in with bad news. The various attacks throughout the world. The teens consider this to be the end. Mr. Hartford points out they still have their genetic powers. Mack agrees and the teens leave to battle. Meanwhile, Mig and Kamdor have arrived at Stone hedge. They figured a legendary place would be ideal to hide a legendary jewel. The teens soon arrive on their vehicles. The teens, using their abilities, battle Mig and Kamdor. Despite their best efforts, the teens are defeated by Kamdor and Mig. Kamdor and Mig are pleased until Mig is suddenly encase inside a tree. Green Mystic Force Power Ranger has arrived. Kamdor is stunned when also Red S.P.D. Power Ranger, Yellow Dino Thunder Power Ranger, and Blue Ninja Storm Power Ranger arrived. Mig managed to break free from the tree. Kamdor and Mig are blasted off their feet by Black Mighty Morphin Power Ranger. The teens are stunned as the five Rangers come together and tell them they heard they needed some help.
Kamdor and Mig decide time to retreat. The five Rangers demorph. Both sets of teens walks towards each other and begin talking. Before the conversation gets too deep, Tori thinks perhaps another place would be a better place to talk. Sentinel Knight appears and he tells them how he brought the five teens, Adam, Xander, Kira, Bridge, and Tori here and agrees the meeting should be held elsewhere. Everyone goes to the control center. The Operation Overdrive teens figure out the five teens are former Rangers. Bridge tells them they are, except for him, who is from the future. Bridge goes into a complicated story of his various Ranger colors and only Dax seems to make sense of Bridge's story. Sentinel Knight appears and introduces the new Rangers and tells everyone they will be the new Operation Overdrive team. Ronny, Rose, Dax, Mack, Will, and Tyzonn are stunned. Mr. Hartford is surprised as well, but doesn't say anything. Later, Rose, Dax, Mack, Will, Tyzonn, and Ronny try to make the best of their sudden amount of free time in the mansion. Kira, Tori, Adam, Bridge, and Xander walk in excited about the zords they will be driving. This doesn't set well with the rest of the teens. Mack points out that they seem to be getting along well and Tori tells them they are. Kira sees the looks on Dax, Mack, Will, Tyzonn, Ronny, and Rose's faces and tells them they will be back as Rangers as soon as they get their powers back. Ronny points out if they get their powers back. The alarms goes off and Tori, Adam, Bridge, Xander, and Kira race out the door. Mack, Will, Tyzonn, Ronny, Rose, and Dax are ready for action as well, but realize there is no place for them. Ronny tells them she is not staying where she is not needed. Elsewhere, Flurious has his Chillers set up a huge road block, so he will not be disturbed as he hunts for the jewels. Black Ranger, on the Hovertek Cycle, arrives and begins the battle. Soon the rest of the Rangers arrive as well. The five Rangers battle the Chillers and defeat them. Flurious is not happy and he retreats. Later, Adam is in the control center, trying to help Mr. Hartford with all the repairs. Mr. Hartford appreciates Adam's help. Adam tells him of his battles with Rita Repulsa and Lord Zedd. Adam believes Thrax has inherited the worst of both his parents. Mr. Hartford is frustrated as he doesn't understand the technology to fix the morphing grid. Adam gets an idea and leaves. Meanwhile, Flurious storms into Thrax' lair. The rest of the villains are there as well. Flurious tells Thrax he may have gotten rid of the Operation Overdrive team, but more Rangers are popping up. Thrax brings forth a monster to help them in their battle against the Rangers. As the rest of them battle the Rangers, Thrax plans to go after Sentinel Knight and have his revenge.
Inside the mansion, Ronny, Rose, Dax, Mack, Will, and Tyzonn face Mr. Hartford. The teens tell Mr. Hartford that although they have enjoyed being Power Rangers, they feel they are no longer needed. The new team of Operation Overdrive is doing well. Mr. Hartford protests, telling them they are still needed. Ronny tells Mr. Hartford they had dropped everything to be Power Rangers, and now they no longer are. The teens want to go back to their lives before becoming Power Rangers. Mr. Hartford asks Mack if this is the same for him. Mack tells his dad he is not going anywhere, but he no longer considers himself a Power Ranger. Mr. Hartford has no choice but to accept the fact that the teens plan to go back to their normal lives.
Flurious, Moltor, Kamdor, Miratrix and the Fearcats have gathered inside the cave. They are not happy. Benglo: We're no better off now than we were before. Moltor: He's right. We've got new Rangers and no jewels. Thrax' plan is failing. Miratrix wanted to know where Thrax was. Flurious commented that he had his Chillers following the new Rangers, but perhaps he should have them following Thrax.
Adam, Bridge, Xander, Kira, and Tori are in a warehouse in Angel Grove. Adam is leading them along. Bridge offers to help and takes his glove off to take a reading. Bridge tells them he is getting a strange reading over by some crates. The strange reading turns out to be several Chillers. Xander steps forward, ready to put his plan into action, and introduces himself. The plan does not go well as Xander is knocked aside by the Chillers. Xander gets up. The five teens battle and defeat the Chillers. Afterwards, Adam spots the crate he was looking for and leads the others to it. Tori wonders whether this would really help, and Adam is confident that it will. In the control center, Mack is sweeping up. The Sentinel Knight appears and tells him he is glad that not everyone has abandon the mission. Mack remarks this is as much as he can do. Sentinel Knight reminds him of what the Rangers had quoted, once a ranger. Mack remarks how can he fight evil when he is no longer a Ranger. Sentinel Knight tells him as long as he fights against evil, he is a Ranger. Mack asks Sentinel Knight what Thrax meant about an object that could destroy him. Sentinel Knight tells Mack about the Excelsior sword. Sentinel Knight believes Thrax is looking for it and when he finds it, he plans to have his revenge on him. Mack excitedly tells Sentinel Knight they should look for the sword. Sentinel Knight replies the protection of the jewels is more important. Sentinel Knight becomes weak and has to leave. Elsewhere, Ronny had just won another race. Ronny glances inside her trophy and is disappointed there is no small box inside. In New Zealand, Dax is filming a movie. Dax had just finished his sequence and everyone tells him he has done great. There is a call for a lunch break and everyone leaves Dax hanging on the wires. Will had just recovered a stolen painting and he has returned it. Will suggests better security and is thanked and given a check. The check doesn't give him the same satisfaction as being a Ranger had. Rose is lecturing at a university. After the lecture, Mack pops his head in. Rose is thrilled to see him. Rose and Mack hug. Mack asks her if she knows anything about the Excelsior sword. Rose replies there is a book in the library about it. Mack takes off. Rose gets on her cell phone. Meanwhile, Mack has found the information he needs and is now in the woods. As he searches, he falls into a pit. Mack manages to climb out and when he does, he sees a goddess statue with the Excelsior sword. Before Mack can do anything, Thrax appears. Thrax tells Mack he has lead him to the sword.
Thrax is ready to strike Mack when his staff gets knock aside by Dax. Mack is surprised and asks Dax how he got here. Dax tells him by following them and points to Rose, Will, Tyzonn, and Ronny. Mack is very happy to see them. In the control center, the crate is open and Adam helps Alpha 6 out. Alpha 6 is very happy to be in service again. In the woods, Thrax is determine to get the Excelsior sword. Thrax approaches the warrior goddess and tries to take the sword, but tge goddess knocks him down. Thrax next uses force to get the sword, but is knocked down once more. Mack tells Thrax he knows nothing of the statue. Only the warrior goddess can decide who gets the sword. An angry Thrax vows if he cannot have the sword, he will destroy the Earth. Back in the control center, Adam and Mr. Hartford prepare Alpha to go into the universal morphing grid and repair it. After Alpha is gone, the alarm goes off. Tori, Kira, Bridge, and Xander slid down the poles and race towards the screen. The screen shows a giant size monster, Vulturus. Tori comments that she sees they still make them big. Mr. Hartford instructs Adam to take the Flashpoint. The five teens race out. In the woods, Dax tries to pry the sword from the goddess, but has no luck as he stumbles back into his friends. Ronny comments that if they were Power Rangers, the goddess would give them the sword. The teens start to walk away, with Mack trailing the group. Mack stops as he remembers what Sentinel Knight say about being a Ranger and having power. Mack tells his friends he is not going until he has the sword. Mack returns to the statue and tries once more. Mack is surprised and pleased as several more hands appear, his friends, and they all try to get the sword. The statue comes to life, much to their surprise, and tells them their friendship and dedication has made her decide to give them the sword. After the sword is passed to Mack, the goddess returns to statue form. In the morphing grid, Alpha is in a panic and wonders what Zordon would do. Meanwhile, the Rangers in the two Megazords battle Vulturus. The Rangers have a difficult time and spot Mack racing towards them with the sword. Mack leaps high into the air and comes down slashing the sword through Vulturus and destroying him. The Rangers cheer.
The six teens return to the control center. Mr. Hartford and Spencer are there, along with Sentinel Knight. Mack gives Sentinel Knight the sword and tells him now Thrax will not be able to destroy him. Sentinel Knight takes the sword and is returned to his true form. Rose tells Mr. Hartford it was wrong for them to have left and they would like to come back. The five Rangers enter the room and tell Mack what a great job he did. Alpha 6 returns from the morphing grid. Mr. Hartford checks and the morphing grid is repaired. The six teens are thrilled as they realized they are Power Rangers again. Alpha 6 tells them it's great to be useful again and Dax adds tells us about it. In the city the evil alliance finds Vulturus on the ground. Thrax is upset, he was sure Vulturus would destroy the Rangers. Flurious tells him he has found with the Rangers it always good to have a plan B. Flurious plants one of his gyros inside Vulturus. Vulturus returns and is now giant size. Back at the control center, the screen shows the evil alliance. Adam asks Mack if he ready to get back into action and Mack replies that he is. The Trackers are handed back to the six teens. All of the teens take off to face down the evil alliance.Thrax is surprised to see the Operation Overdrive teens. All the teens morph. The Rangers and the villains race towards each other and the battle begins. Black Mighty Morphin Power Ranger battles Thrax. Red S.P.D. and Red Operation Overdrive Power Rangers battle Flurious. Green Mystic Force, Black Operation Overdrive, and Blue Operation Overdrive Rangers battle the Fearcats. Yellow Dino Thunder and Yellow Operation Overdrive Rangers battle Miratrix and Kamdor. Blue Ninja Storm and Pink Operation Overdrive Rangers battle Moltor. Mercury Ranger battles several Chillers and Vulturus. It is a difficult battle, but the Rangers are doing well. Mercury Ranger destroys Vulturus. Sentinel Knight appears. Thrax tells him if he had the sword he would destroy him. Sentinel Knight replies he can't have the sword, because it is now a part of him. Sentinel Knight destroys Thrax and ends the evil legacy. The Rangers, Sentinel Knight and the remaining evil alliance face each other. The Rangers and Sentinel Knight fired at the Evil Alliance. The villains survive and Moltor tells them he is going after the jewels. Miratrix tells him not if they get there first. The Evil Alliance is no more and they vanish. The Rangers and Sentinel Knight walk forward. Red Operation Overdrive Power Ranger tells Black Mighty Morphin Power Ranger that is what Ranger power is all about. They shake hands.
Everyone is gathered inside the Hartford mansion, including all the teens, Mr. Hartford, Spencer, and Alpha 6. Dax tells Tori, Xander, Bridge, Adam, and Kira that at first he was happy to see them, then upset that they were staying, and now sad that they are leaving. Spencer walks in with a tray full of buttery toast for Bridge. Tori tells them if they ever need them again, just to give them a call and passes her card over to Mr. Hartford. Adam plans on taking Alpha 6 back to his dojo with him. Everyone is in an upbeat mood. Mr. Hartford suggests they gathered together. Everyone forms a circle and plans their hands on top of each other. Then they leap into the air and cheer for Power Rangers.
|Mighty Morphin Black Ranger||Adam Park||Johnny Yong Bosch|
|Blue Wind Ranger||Tori Hanson||Sally Martin|
|Yellow Dino Ranger||Kira Ford||Emma Lahana|
|S.P.D. Red Ranger||Bridge Carson||Matt Austin|
|Green Mystic Ranger||Xander Bly||Richard Brancatisano|
- James MacLurcan as Mack Hartford (Red Overdrive Ranger)
- Samuell Benta as Will Aston (Black Overdrive Ranger)
- Gareth Yuen as Dax Lo (Blue Overdrive Ranger)
- Caitlin Murphy as Ronny Robinson (Yellow Overdrive Ranger)
- Rhoda Montemayor as Rose Ortiz (Pink Overdrive Ranger)
- Dwayne Cameron as Tyzonn (Mercury Overdrive Ranger)
- Nic Sampson as Sentinel Knight (voice)
- Johnny Yong Bosch as Adam Park (Mighty Morphin Black Ranger 2)
- Sally Martin as Tori Hanson (Blue Wind Ranger)
- Emma Lahana as Kira Ford (Yellow Dino Ranger)
- Matt Austin as Bridge Carson (Red S.P.D. Ranger 3)
- Richard Brancatisano as Xander Bly (Green Mystic Ranger)
- Rod Lousich as Andrew Hartford
- David Weatherley as Spencer
- Gerald Urquhart as Flurious
- Mark Ferguson as Moltor (voice)
- Adam Gardiner as Kamdor (voice)
- Ria Vandervis as Miratrix
- Kelson Henderson as Mig (voice)
- David Weatherley as Benglo (voice)
- Glen Levy as Thrax (voice)
- Campbell Cooley as Vulturus (voice) & Alpha 6 (voice)
- ??? as Generalissimo (voice)
- Shanez Aarron as War Goddess
Jackie Marchand has said the episode was difficult to create, as they needed to balance between the action, the drama, and the returning cast with the Overdrive team. There were some extra scenes to explain why the Overdrive team is quitting, which were cut from the episode: Marchand says the aired version "didn't reflect well on the Overdrive team and made them seem like assholes". 
- When Thrax severs the Morphin' Grid sending the rangers to their knees, the rangers are seen with different effects on their morphers. Some have error messages on their screens while some morphers are just outright destroyed.
- This marks the first appearance of Sentinel Knight's Super Form.
- Bridge's Aura reading ability has changed color. When he was the green ranger it was green and now it's red, matching his new color.
- Rita Repulsa, Thrax' mother, became the Mystic Mother in Power Rangers Mystic Force, though Xander strangely did not relate the two together.
- As of Power Rangers Super Ninja Steel's "Dimensions in Danger", this is the only anniversary episode not to feature Tommy Oliver, T.J. Johnson or Wesley Collins although Tommy is mentioned by his teammates Kira and Adam.
- This is also the only anniversary episode not to feature the Suit of the Red Mighty Morphin Power Ranger.
- As secondary abilities weren't made commonplace until the Disney era, Adam is the only ranger featured without a special ability when he isn't morphed. Instead his natural karate ability is on display. Adam makes a reference to this fact noting his fighting style is "old school" but it "still gets the job done".
- It is unknown when Thrax was born. It could be possible, out of many other theories, that he was born prior to the destruction of the United Alliance of Evil by Zordon's Energy Wave.
- It is unknown how Alpha 6 ended up on Earth, as Alpha 6 was last known to be on Mirinoi. It is also unknown how his voice shifted from a feminized Alpha 5-like voice to an over-synthesized male one.
- Potentially the intent may have been to activate a previous Alpha-series robot and Not Alpha 6, only for them to be unable to find the Alpha 5 suit due to the sale of assets that had occurred amidst the transition to Disney's production in New Zealand. During the Alien Rangers miniseries, there was seen the remains of a decommissioned Alpha series robot believed to have been Alpha 4 in Storage underneath the command center, which tied directly to knowledge Adam would have to then retrieve it from the warehouse The Zeo Rangers had previously transferred all of those supplies to during the events of Zeo.
- Angel Grove makes an appearance, its first since Lost Galaxy's Quasar Quest.
- Adam receives a new Morphing sequence. Adam doesn't yell "Mastodon" during the morph sequence and he also utilizes a more detailed preparation sequence only seen once before in the season 3 episode Ninja Quest Part: I.
- However, in the polish dubbing Adam yells "Mastodon" instead of "It's Morphin Time!".
- Bridge, having changed colors, also received a new morph sequence. It doesn't end with Jack's battle cry ("S.P.D. Red Ranger!") or the pose, instead his stance is more like Sky's when he was morphing into the Red Ranger. Bridge's morph is similar to the Cat Ranger morph, likely due to both (Cat and Bridge's Red) only being used for one episode each and not worth doing the more elaborate morphs of the other S.P.D. Rangers.
- Bridge mentioned Cruger in part 1.
- During Mack and Bridge's battle with Flurious, Bridge tosses his Delta Blasters to Mack. In GoGo Sentai Boukenger vs. Super Sentai, AkaRed, being the embodiment of the Red Sentai Spirit, grants the use of the Delta Blaster's counterpart, the D-Magnums along with weapons of other Sentai Red Rangers, to Bouken Red.
- Adam also seems to have the ability to use the Defender Vest, although it may have been a modification by Andrew.
- During his battle with Thrax, Adam yells out, "Morphinominal!" a phrase coined by Kimberly Ann Hart (Amy Jo Johnson) in the original Mighty Morphin' Power Rangers.
- Kira tells the Overdrive Rangers "I'm sure you'll be back to action in no time", a throwback to the battle cry Jason coined in the Mighty Morphin' era of Power Rangers when the rangers would return to battle while partially in their morphed suits, "back to action".
- Adam is shown using Will's hover cycle, keeping in line with the vehicle being built for use by a black ranger.
- During Adam's morphing and fighting sequences. an unnamed soundtrack that used high-pitched instruments was used rather than the "Go Go Power Rangers" theme song. It was believed the reason was due to copyright issues, however this would not have made any sense considering that Disney (at the time) owns the rights to Power Rangers and that technically includes usage of the original theme song as it was heard in the Dino Thunder episode, Legacy of Power. Also, at the end of the second episode, all eleven Rangers and Andrew put their hands together and called out, "Go Go Power Rangers!".
- It's unclear how Xander knows anything about piloting actual Zords, as the members of Mystic Force themselves transformed into their Zords.
- Thrax' "Evil Alliance" could be a reference towards Dark Specter's United Alliance of Evil (an alliance his parents were apart of).
- This is the first time in the history of the series where another team of rangers pilots the current team's Zords.
- Adam, Bridge and Xander were all Green Rangers at one point in time. Xander, however, is the only one of the three who still used his Green Ranger powers.
- Once A Ranger is the fourth team-up in Power Rangers history to feature a combined team of 11 Rangers, proceeded by Power Rangers Zeo/Mighty Morphin Alien Rangers, Power Rangers Lost Galaxy/Power Rangers In Space, and Power Rangers Dino Thunder/Power Rangers Ninja Storm. It is also the second time that Veteran Rangers from more than 2 seasons team-up, the first one being Forever Red, which also commemorates the tenth anniversary of the Power Rangers Franchise.
- The color choices for the team may be a reference to Voltron, including having the black themed ranger as the leader.
- Right as the roll-call starts, usually it's the previous Power Ranger team who goes first then the newest Ranger team does their roll-call, instead the newest team roll-called and the Retro Rangers went second. In the roll-call, however, they all just grunt as they pose.
- Aside from the Overdrive Rangers and Sentinel Knight, Tori is the only Ranger whose Japanese counterpart, Nanami/HurricaneBlue, was in the Japanese counterpart of this team-up, GoGo Sentai Boukenger vs. Super Sentai.
- Moltor, Kamdor, Miratrix, and the Fearcats are the only characters with either direct or semi-direct Boukenger counterparts whose counterparts were not part of GoGo Sentai Boukenger vs. Super Sentai. Only Flurious' counterpart, Arch Priest Gajah, was included in Boukenger's team-up.
- Adam is the only Ranger where no one from his Japanese counterpart's team (Kyoryu Sentai Zyuranger or Gosei Sentai Dairanger, depending on one's point of view) appeared in GoGo Sentai Boukenger vs. Super Sentai (When he originally used the Mastodon Coin, Adam had MammothRanger's suit, but used ShishiRanger's mecha, Mythical Chi Beast Star-Shishi).
- Although Tsubasa Ozu is not Xander's counterpart, Tsubasa's actor Hiroya Matsumoto's counterpart still appeared in this team-up as Nic Sampson/Charlie Thorn voiced Sentinel Knight.
- This is the first time that the series used New Zealand as the country itself when Dax goes back to stunt work in part 2.
- Both this team-up and the Forever Red team-up involved having some type of weapon or villain having to do with Rita Repulsa and Lord Zedd.
- The Sentinel Knight said that he restored the powers of the previous Rangers, however, Xander and Bridge's powers were not destroyed.
- This is also the second time Adam has morphed into the Black Mighty Morphin Power Ranger outside of the MMPR era.
- Kira had already met two of the other rangers prior to this episode, although she didn't mention it. Given, she only remembered having met Tori during the Ninja Storm-Dino Thunder team-up, as after both Dino Thunder-S.P.D. team-ups, she had her memory of the events erased, so she didn't remember ever meeting Bridge.
- As with the majority of the season, 'Once a Ranger' received overwhelmingly negative reviews from fans and has even been considered to be the worst team-up of the entire franchise. The main subject of criticism is the fact that the Overdrive Rangers chose to give up their duties as rangers instead of continuing to fight against evil despite losing their powers.
- This is the second and final time Tori is seen helmetless. The first was "Prelude to a Storm".
- When working on the Morphing Grid Alpha 6 mentions Zordon appropriately asking "What would Zordon do?", a possible allusion to his godlike status in the Mighty Morphin' era of Power Rangers as an alternate version of the phrase "What would Jesus do?".
- Final appearance of the Mystic Force Fighters, used by Xander.
- Adam, Tori, Kira, Bridge and Xander would appear one last time morphed in "Legendary Battle".
- In the helmetless retro Rangers scene, Kira and Xander's holster weapons are on the wrong sides of their respective belts.
- GoGo Sentai Boukenger vs. Super Sentai - Super Sentai counterpart in Boukenger. See comparison page. (story)
- Task. 29: The Golden Sword - Super Sentai counterpart in Boukenger. See comparison page. (fight footage)
- Task. 30: The Rage of the Golden Majin - Super Sentai counterpart in Boukenger. See comparison page. (fight footage)
- Task. 32: The Secret of the Adventure School - Super Sentai counterpart in Boukenger. See comparison page. (Generalissimo's costume)