Thread:JeloElducal/@comment-27480112-20181025121117/@comment-30384301-20181027044127

Olympus. It happened in The Portal Problem, but Olympus managed to defeat them and imprison them for almost a year. He was only defeated when the gang showed up in Starcade's debut episode and helped Starcade.

The Nitrome Boss was the second one, who tyrannically rules over Nitrome where the Retro Rebels except Starcade used to live in. He was killed in Nitro Mania once he is trapped in his self-destructing base.

By the way, Olympus built his empire and city after Nitro Mania on the lands of Nitrome, which means that he took over the Nitrome Boss after the latter is deceased. Which also means that Champion City replaced Nitrome.