Ehra, Corrupted Forest Spirit

{b}{g}: Put a -1/-1 counter on target creature.
{1}{b}{t}, put a -1/-1 counter on Ehra, Corrupted Forest Spirit: Destroy target creature with a -1/-1 counter on it.
{1}{g}: Regenerate Ehra, Corrupted Forest Spirit.
As the forest started to wither, its guardian withered with it.