|This article is about a/an artifact in Mirai Sentai Timeranger.|
The Control Key (制御キー Seigyo Kī) is a special key used by Don Dolnero as a means to try and keep his cyborg partner Gien under his will. It was granted to him by the scientists who turned the poor youth critically wounded by officers into a cyborg in order to turn off his computer mind and restore his original idiot personality, but Dolnero never used the artifact due to how the genius gained by Gien allowed for him to assist in his own criminal activities.
After an incident where Hell's Gate Prisoner Emboss is released upon 21st century Tokyo with its fatal effects forcing Dolnero to use his own blood to stop it, he is forced to re-insert the Control Key into Gien in order to finally bring his madness under control and return to his own criminal activities under the radar. However, this key is removed by Captain Ryuya due to his own plans to speed up the Great Annihilation with the cyborg's mental decay as the means to bring it about. With Gien beginning to collect Lambda 2000 once again, Dolnero is forced to work with the Timeranger to create a second Control Key to stop Gien. But before it can be inserted into the cyborg, Ryuya destroys it to prevent anyone from getting in the way of his own plans.