On Omnitron’s villain character card it states: “When Omnitron is destroyed, remove Omnitron’s villain character cards from play. The heroes cannot win until there are no devices in play.” Once you destroy the remaining devices, the game will end in victory. However, there’s no guarantee you’ll win, because Omnitron will still have a turn and play a card as usual. Any effect that says Omnitron itself deals damage will be ignored, but watch out for those Electro-Pulse Explosives!

Since Luminary has devices of his own, they will also prevent you from winning the game. The same thing can happen in the Omnitron-IV environment. Watch out!