Gamora, Sole Survivor

Whenever Gamora, Sole Survivor deals
combat damage to a player, bolster 1.
(Choose a creature with the least toughness
among creatures you control and put a +1/+1 counter on it.)
{b}, {t}, Sacriface Gamora, Sole Survivor:
Search your library for an artifact card,
reveal it, put it into your hand, then shuffle
your library.