Heavy Lies the Crown

Four kingdoms are stuck in a perpetual war. If they make their move, the joker will make his, and so they've been stuck like this for centuries. Sabo decides he's had enough, that he'll end it, even if the other three kings become casualties to bring about that end. But when he kills the first, Ace, he doesn't expect to be stuck with him until his goal is met-if his sanity lasts.