Cynth, Vengeful Knight

Dethrone (Whenever this creature attacks the
player with the most life or tied for most life, put
a +1/+1 counter on it.)
Persist (When this creature dies, if it had no -1/-1
counters on it, return it to the battlefield under
its owner's control with a -1/-1 counter on it.)
Creatures you control have Dethrone and Persist.