Sammi, Hand of Corruption

When Sammi deals combat damage to a player,
you my sacrifice a creature. If you do, distribute a number of -1/-1 counters equal to the sarificed creature's toughness amoung any number of
target creatures.
At the begining of your end step, gain control of
target creature with a -1/-1 counter on it for as
long as you control Sammi.