"Prior of the main event of the storyline, Umarak was created in the island of Karzahni, which was ruled by the ruler called Karzahni alongside the other being called "Devastator". Later, he and " Devastator" were approached by "The Shadowed One ", leader of the Dark Hunters who then offered them of their services. Eventually, both of them accepted and serve him as the members of the Dark Hunters.
Despite joining in the Dark Hunters rank, Umarak often spends time with himself and also operate in the mission that "The Shadowed One" assigned him alone.
The Power That Be
Although Umarak did not appear in the storyline, he was seen in the end sensing his master's defeat and banishment into the Zone of Darkness as he decided to make his move and declared that he will free his master to help him conquer the Matoran Universe once and for all."
Correct me if I'm wrong, but...
Umarak wasn't in G1, now was he?