I understand he seems to want to stop the Legion when they eventually invade. But doing his quests, the way he carries himself screams "villain". I haven't done all the quests to date yet, but he wants to "reshape Azeroth' and seems to be very ambitious.
I'm not saying he will be a villain any time soon. After the Legion expansion, Blizzard is going to need to find new villains. Perhaps after we stop the Legion, we find some more titan artifacts, and Wrathion takes it upon himself to use them to reshape Azeroth? I think he would be a unique villain (at least in terms of WoW). Instead of being corrupted by the Old Gods, or a tyrant, Wrathion could end up being some sort of anti-hero. And I know some might say "omg another good guy turned bad" but that would be wrong, because Wrathion would have been a "bad guy" all along.
Anyone else agree he would make a great villain?
NOTE: Someone can both be an anti hero and a villain. They aren't mutually exclusive. I'm not saying Wrathion is evil.
Villain definition - A dramatic or fictional character who is typically at odds with the hero.