Norn the Destiny Sisters

Defender
Whenever a creature you control enters the battlefield, you may sacrifice another creature. If
you do, put X +1/+1 counters on that creature,
where X is the sacrificed creature's power. Then
put X -1/-1 counters on target creature you do
not control, where X is the sacrificed creature's toughness.
Sometimes, tampering with fate is irresistible.