My first character and the only one I got to 50 (not for the lack of trying...): Silver Spartan, a soldier from an alternate Earth where the battle at Thermopylae went very, very differently (and several milennia later, Frank Miller wrote "10 000").
His backstory was not a serious effort, mashing together references to 300 and Halo, but he ended up growing on me more than I ever expected.