Gaisoulg

Gaisoulg (ガイソーグ) is a set of animated knight armor which developed its own evil sentience with an insatiable desire to hunt strong opponents to make them hosts against their will. His evil spirit was a enemy of the Ryusoulgers until the armor was purified later thanks to Jack-o'-lantern Minosaur's power and put under the ownership of Nada. The armor was manifested into the Max Ryusoul Changer and Max RyuSoul after its user's death.

Character History
According to Bamba, Gaisoulg was created by the RyuSoul Tribe to fight the Druidon, however at some point the armor developed its own consciousness. Master Green would later don Gaisoulg's armor against some returning Druidons, but ultimately, the Armor found his weakness and managed to control him, causing him to attack his own village. Unable to deal with it, Master Green fled to outer space and died off, leaving Gaisoulg to wander the cosmos looking for a strong opponent. Eventually, he ended up on planet Nemesis.

Super Sentai Strongest Battle!!
Gaisoulg is an armored Ranger-like knight who bears more than a passing resemblance to the Ryusoulgers. He has been searching for the strongest among the Super Sentai, and initially sought out the Gokaigers. Dissatisfied with them, he leaves. Later he infiltrates the Super Sentai Strongest Battle, a friendly competition among Rangers to discover the strongest warrior and grant their wish, in order to achieve his ends. Captain Marvelous also receives an invitation to the battle and surmises correctly, that it is the perfect place for Gaisoulg to attack next.

Gaisoulg then proceeds to attack some of the skirmish winners, until he gets to Stinger and Takaharu Igasaki, who happen to be part of Captain Marvelous' component. Gaisoulg attacks the duo until Marvelous arrives to fight him. Gaisoulg is able to defeat him but before delivering a final blow, Takaharu deflects one strike and is hit by the other. He decides to leave afterwards and is summoned by Rita, the guardian of Nemesis who created the competition. She says that only those with an invitation are allowed to participate but Gaisoulg reveals he is in possession of one. With no other choice, Rita inserts Gaisoulg into the competition as a wild card. Between rounds, Gaisoulg confronts Takaharu and attacks him. Gaisoulg is sent into the fight between NinjaWhite & RyuuRanger vs. Red Mask & OhRed in order to speed things up. The four Rangers anticipated this and teamed up to fight Gaisoulg but were all defeated until Marvelous arrived and fought him as Gokai Red then as DekaRed and HurricaneRed. Gaisoulg prepared to use one of Takaharu's techniques but was deflected by Marvelous who was able to unmask him, revealing Takaharu Igasaki inside.

After Ultimate Dai-Satan is defeated, Rita summons Gaisoulg's armor to fight against Marvelous, Stinger, Takaharu, Kagura and Yamato. RyusoulGreen and RyusoulBlack appears and finish off Rita by destroying Gaisoulg's armor in order to release her. After Gaisoulg's armor has separated into pieces, an unseen person manages to take Gaisoulg's helmet before making his leave.

Ryusoulger
Nada, now under the identity of Gaisoulg, released Kishiryu DimeVolcano for Wizeru, however the Kishiryu was obtained by the Ryusoulgers first. The night after the Ryusoulgers defeated the Shen Minosaur, Gaisoulg met with Wizeru and Kureon mocking the former of the two for allowing the Ryusoulgers to obtain DimeVolcano, which made Wizeru angry and had a small fight with him. Angrily Wizeru asks him why he didn’t got rid of the Ryusoulgers by himself which Gaisorg responded that it was pointless as Wizeru wanted "entertainment". Gaisoulg tells Wizeru that he's going to let him know if he finds something interesting before leaving.

Gaisoulg later approached Prime Minister Mioko Karino at her hospital room who tells her that he could have killed her if she wanted. Mioko responded that she and Gaisoulg are similar as both wander with nowhere to belong. Mioko tells Gaisoulg that he might be having trouble to let his past glory go and according to her, Gaisoulg could create a Minosaur by this rate. While Mioko leaves, Gaisoulg asks her where she’s going, to which she answers where she belongs as she finally found her place.

After a seven episode absence, Gaisoulg returns by meeting face to face with Towa who was the last Ryusoulger standing as the others were captured by Wizeru with the power of the Grimoire Minosaur. Gaisoulg had a small battle with Towa in which he easily defeated him. Before leaving, Gaisoulg told Towa “to not rely on his strengths and bring them to life instead” which were the same words that Towa and Bamba’s master used to say.

Nada eventually reaches to the point where he cannot control Gaisoulg, thus letting the armor taking over his mind.

Gaisoulg made its way to the Ryusoulgers while the latter were fighting Gachireus and Jack-o'-lantern Minosaur, the Druidon Tribe members retreats as Gaisoulg rampages on site. Suddently, Towa use DoshinSoul to weaken Nada's body as a mean to force Gaisoulg to switch to a new host, and Melt suggests to use the Minosaur's rainbow rain to accelerate the process to exhaust Gaisoulg's hatred. Gaisoulg attempted to take Koh as its new host but was blocked by the Ryusoulgers and its hatred was expelled by the rainbow rain, relieving Nada and Koh.

After defeating the Jack-o'-lantern Minosaur, the Ryusoulgers return to the Tatsui residence. Nada secretly follows in as Gaisoulg, frightening Ui and Naohisa untill surpise them by using the Gaisoul Ken as a backscratcher. Then Nada took off Gaisoulg's helmet, showing his gratitude to the Ryusoulgers and giving Towa a payback fight upon using DoshinSoul on him.

Personality
Not much known about his personality. It is shown that he is a merciless and sadistic knight who wanted to defeat his enemies without any villains' help. He is also one of the Sentai villains with a loner-type personality. The armor has an insatiable craving for a strong opponent, and will often take over the strongest body in the vicinity. Eventually, it was revealed to be possessed by excessive amounts of hatred, which was drained thanks to the Jack-o'-lantern Minosaur. After the essence of hatred is released and vanished, the Gaisoulg armor is later used for good by Nada to aid the Ryusoulgers.

Users
These people used the armor and unlike the hosts, they have full control over it or they still have control over their actions prior to the armor's purification.

Hosts
Prior to the armor's purification, these people were forced to wear the armor against their will and while using it they had almost no control over their actions, depending on how many parts of the armor is worn, like Captain Marvelous, who partially held-in the armor's essence until he freed the others that it captured. In Koh's case, despite not having the complete armor, he could still access the past user's memories.

Arsenal


"Gaisoul Change! (rock riff) Haa~"

- Transformation announcement via Gaisoul Ken


 * Gaisoul Ken (ガイソーケン): A purple version of the Ryusoulgers' Ryusoul Ken.
 * Unnamed Shield
 * RyuSouls
 * GaiSoul

Attacks
 * Ancient Break Edge (エンシェントブレイクエッジ): Gaisoulg signature attack. With the Gaisoul Ken, Gaisoulg gathers energy and unleashes two energy slashes that combine to form an "X" slash before hitting the target.
 * Projectile Energy Blade Attack: Throw energy slashes with Gaisoul Ken to the opponent.
 * Luka's Gokai Saber technique
 * Takaharu's Shuriken Ninpo

Powers & Abilities Appearances: 4 Week Continuous Special Super Sentai Strongest Battle!! Episodes 1-4, Kishiryu Sentai Ryusoulger Episodes 12-13, 20, 26-27, 29-33, Kishiryu Sentai Ryusoulger The Movie: Time Slip! Dinosaur Panic!!
 * User Possession / Host Subjugation: Being a living armor, Gaisoulg can subjugate others to be able to use them as his body, as long as the person he is going to possess is strong enough to use it, hence his desire to seek and fight with strong warriors to take possession of them. The stronger the host you own, the more time you can use it to the point where the host cannot control your own actions. While under his will, the host has access to the memories of previous Gaisoulg host. It has been seen that Gaisoulg can even possess those who wear even any part of his armor, such as Captain Marvelous who was almost possessed by having Gaisoulg's helmet, and Koh having almost all of the full armor. Gaisoulg can also access the attacks of his hosts, he could already use the Luka's Gokai Saber technique and the Takaharu's Shuriken Ninpo when he owned them. However, there have been certain people, unlike the hosts, who had total control over Gaisoulg and still had control over their actions when they used the armor of their own free will. Those people are: Valma, Master Green (the first original user until he became a host later), Rita and Nada (he also became a host later when he can no longer control the armor).
 * Invisibility: While it’s unknown if he can access to this ability via KakureSoul like the Ryusoulgers or is a power belonging to a host. It’s confirmed that Gaisoulg can turn himself invisible to sneak into any place he wants.
 * Minosaur Creation: According to Mioko Karino, Gaisoulg is capable of creating Minosaurs, much like herself or Kleon.

Portrayal

 * Gaisoulg is voiced by Tomokazu Seki (関 智一), who previously voiced as Mepple in Futari wa Pretty Cure, Buldont in Choriki Sentai Ohranger and the Narrator and the voice of the Gokaigers' equipment in Kaizoku Sentai Gokaiger, while also voicing the Ryusoulgers' equipment. His suit actor is Riichi Seike (清家利一).