Ultros, Obnoxious Octopus + Agatha's Soul Cauldron + Crystalline Crawler + Fanning the Flames

Ultros, Obnoxious Octopus

Agatha's Soul Cauldron

Crystalline Crawler

Fanning the Flames

How it works

1. Cast Fanning the Flames with buyback by paying 6.
2. Ultros's first and second abilities trigger, tapping a creature an opponent controls and putting a stun counter on it, and then putting eight +1/+1 counters on Ultros.
3. Resolve Fanning the Flames, dealing 3 damage to any target and returning it to your hand.
4. Activate Ultros using Crystalline Crawler's first ability eight times by removing eight +1/+1 counter from it, adding 6.
5. Repeat.