Master Key
From Transformers Wiki
TheMaster Key(マスターキーMasutā Kī) is what givesMini-Consfull access to their powers as creations of the evil god,Unicron.
Fiction
Linkage
When the Mini-Cons gained sentience, and broke free from their master's control, the Master Key was locked away, similarly "locking away" the Mini-Cons' powers. However, thanks to the efforts ofRedline,who accquired data from scans of the various Unicron-allied Mini-Cons (who still had access to their full powers as a result of still being slaves to their creator), a method of upgrading the Mini-Cons was devised, allowing them to finally unlock the Master Key and awaken their true abilities.Linkage