Omen is a demon herald of Gargos and the secondary antagonist in Killer Instinct (2013). He is a bonus character in Season 2 (the 5th character of the season and the 14th overall), and is the dark spirit that had possessed the warrior Jago, turning him into Shadow Jago. He is a loyal servant of the astral deity Gargos, and has been given the special duty of preparing the world for the return of his master.

He is the only character of Season 2 to not have his own Rivals Mode story (or even a rival, for that matter) - however, he does make an appearance in several others' as an opponent. In Season 3, several other Omens appear as servants of Gargos in Shadow Lords mode, and defeating each one will weaken Gargos in the coming battle.