Murktide Regent (Showcase) - Modern Horizons 2: (Showcase)

Delve (Each card you exile from your graveyard while casting this spell pays for .)
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.