Actually it is always one path, the thing is, there's actually 2 different quests. One where he turns into a demon, and one where he doesn't. The quests just looks the same until he does... so you think it's random (but it isn't). It's the same with the clearing rat quest, one where you have to fight a spider, one where you don't.
As for confusion, I remember getting it once... it's a battle spell that causes the enemy to become clumsy (50% of not attacking the targeted unit). Not the greatest thing in the world.
