Abbreviation for Obviously, but putting obviously to the maximum. It exudes a greater existance of "obviously" and adds emphasis to the obviously that was first said. In turn, adding omega makes others feel like complete idiots for stating something so extremely obvious.
guy: Dude, you going to the game tonight?
you: Obvi omega. Why do you think i'm wearing this outfit?!
person 1: Wow dude. I've got some major cotton mouth fur shur after that last hit. How 'bout you?
person 2: Obvi omega. Shit son!