Nominus Prime (Earth-9107)

Often called Nominus the Unworthy, and not without reason.

When Nova Prime left Cybertron to begin colonizing other worlds, he left Nominus in charge until he returned. He never did, and so Nominus was made Prime. Cybertron became riddled with political corruption, functionist apartheid, and general Oppression.

However, when the Decepticon movement rose up, they committed the first morally dubious action: Assassinating Nominus Prime.

After this, the incompetent Sentinel was made Prime.