argall (invincible)

A villainous character from the backstory of the comic and cartoon Invincible. He was an emperor of Viltrum who pursued an aggressive policy of galactic imperialism abroad, social darwinism inside his empire (his Grand Regent Thragg dealt up his worst policies of imperialism and social darwinism up to eleven when he came to power after him) and was assassinated by Thaedus after he failed to dissuade him from his aggressive policies.
In the later course of the series, it was revealed that Nolan was his long-lost heir, making him and his son after him the rightful successors to the throne (both actually became emperors of the few remaining Viltrumites, and cemented a species-wide heel-face turn).