Mistrider Envoy

Mistrider Envoy can't be blocked.
Whenever Mistrider Envoy deals combat damage to a player, if it's defiled, draw a card.
Defile 4 — Whenever exactly four cards are put into your graveyard from anywhere, if Mistrider Envoy isn't defiled, it becomes defiled and put a +1/+1 counter on it.