Havengul Lich + Grimgrin, Corpse-Born + Angelic Sell-Sword + A Realm Reborn

Havengul Lich

Grimgrin, Corpse-Born

Angelic Sell-Sword

A Realm Reborn

How it works

1. Activate Grimgrin's ability from A Realm Reborn by tapping Grimgrin, adding one mana.
2. Activate Grimgrin by sacrificing the creature castable for one mana, untapping Grimgrin and putting a +1/+1 counter on it.
3. Activate Grimgrin's ability from A Realm Reborn by tapping Grimgrin, adding one mana.
4. Activate Havengul Lich by paying 1, allowing you to cast the creature castable for one mana from your graveyard this turn.
5. Cast that creature spell from your graveyard by paying it mana cost.
6. When you cast that creature or when it enters, Angelic Sell-Sword triggers, creating a creature token.
7. Activate Grimgrin by sacrificing the creature token, untapping Grimgrin and putting a +1/+1 counter on it.
8. Repeat.