Your character has sworn an oath, hypocritical or not he would stick to it, that is assuming he would stick to it in the first place.
Really, you can have a character that swears not to hurt the helpless who makes sure to slaughter the women and children of a goblin tribe when they finished off the warriors or what have you, in fact you can have him do anything you want, hypocritical or evil or not.
Anyway, many people are hypocritical in life and seem to get along just fine, I don’t see why a character wouldn’t.
Personally I'm of the opinion that a Coup de Grace is more of a neutral act.
Really, you can have a character that swears not to hurt the helpless who makes sure to slaughter the women and children of a goblin tribe when they finished off the warriors or what have you, in fact you can have him do anything you want, hypocritical or evil or not.
Anyway, many people are hypocritical in life and seem to get along just fine, I don’t see why a character wouldn’t.
Personally I'm of the opinion that a Coup de Grace is more of a neutral act.