Aatrox, the Darkin Blade

First strike, trample

Worldender—Whenever Aatrox, the Darkin Blade deals combat damage to a creature, put a +1/-1 counter on Aatrox. Aatrox cannot die from counters.

YOU CANNOT KILL ME!—If Aatrox would die, instead exchange his power and toughness and give him +3 power, remove all damage from him, and Aatrox loses this ability.