Mad Max / Boarderlands Pyscho Champ!

Yeah, this concept is kind of self explanatory. A psycho style character, probably a bruiser/AD type, probably has some kind of ability to ignore damage or continue fighting while low hp, and be able to rage through the enemy. Actually sounds a bit like Olaf. Maybe just a Pyscho skin for Olaf? Either way I'd be happy :).

Ooo or you could make it more on the Borderlands side and it could be an ADC with all sorts of crazy weapons. Each skill could whip out a different style gun and again you could play on the pyscho bit with doing damage after you die or preventing death for a few seconds, or swapping to melee style or some garbage i uno.