If I just had their powers? Deathstroke. That brain would be invaluable on the battlefield. Not to mention the enhanced physical prowess. Being a King sounds great, until you realize you likely aren't cut out to lead a nation. If I had to be them in their respective universes, as in BE their exact character, Black Panther all the way.
But just adopting their powers and abilities to my life, Deathstroke.