Contempt of Purity

Destroy target creature with converted mana cost 3 or less. If that creature was a Unicorn, put X +1/+1 counters on the creature you control with the greatest power, where X is that Unicorn's toughness.
''There are those who are struck with such agony at the contrast of their own purity to a unicorn's that they are compelled to decimate all innocence, tearing our kind to pieces to appease their existential pain .''
- Zarael, Goldhorn Protector