Being a Hero is not a job. Being a Hero is a way of life. Quest is the only thing that matters. Failure? No such thing. Reason? Purely optional. Wisdom? A little wouldn't hurt...
Arthaxiom the Paladin is a Hero. His quest is to destroy the Evil Empire, so that's what he's going to do. What's so evil about it? It doesn't matter. A Hero does not argue with his quests. Nor does he argue with fate. A randomly encountered dwarf? Perfect choice for a sidekick. A village girl in distress? Must be a princess.
But if there's a Hero, there must also be villains. An assassin, who stabs people. Because they were alive and he had a knife. A sorceress, who puts things on fire. Because they weren't on fire before. And there would be the Emperor himself, if he hadn't ended up dead in a moat full of lions. A bunch of quarrelsome High Lords is to choose his replacement. It will surely go well.