Champions who challenge destiny?

I think the rework of Amumu, should it look like in the video, will be really great, specially since his identity as the lonely mummy was kind of weird when he was a popular champion in the Field's of Justice. His own loneliness raising into a murderous tantrum which makes him even more lonely, it's the very essence of despair, a character you really feel sorry for now.

However, it also got me thinking that champions are pretty straightforward when ther story involves destiny, like the curse casted on the Sad Mummy (at least so far, as the story could further develop later in time). If they suffered a wrong, they become murderous, or avengers. If they are destined to greatnes, they are noble heroes. Does anyone remember a character who does the exact opposite of what he was supposed to do by destiny?

So far I can only think of Riven, as someone who saw the cruelty of Noxian genocide as it truly was isntead of the beauty Noxius seems to see on it, but even then she just left the battlefield and did nothing afterwards.