Mongul is going to face the following GLs wearing a single qwardian yellow ring:
Hal Jordan
Kilowog
Kyle Rayner
Guy Gardner
John Stewart
Sodam Yat (as a green lantern)
To this end, Redskull will be providing a little service: With the help of the cosmic cube he will do his best to break the wills of the GL's by torturing them, making their lives miserable and all around destroying their spirits. He has three month's to break them and they face Mongul after wards.
Hal wins.
Kilowog wins.
Yat loses.
Kyle... not sure. depends on whether he's truly over his mother's death. he can win.
Guy is enough of an ass to want revenge afterwards, he wins.
John loses, imo.
Hal Jordan - Asks for more, and tears out Mongul's other eye
Kilowog - Wins, and then molests Kyle
Kyle Rayner -
Guy Gardner - Dies
John Stewart - Drops a solar system on the Cosmic Cube
Sodam Yat - He gets a seizure in the first scenario