Murktide Regent - 52 M MH2

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Flying
This creature enters with a +1/+1 counter on it for each instant and sorcery card exiled with it.
Whenever an instant or sorcery card leaves your graveyard, put a +1/+1 counter on this creature.

mythic
Creature — Dragon
From the Magic: The Gathering set Modern Horizons 2.