Requires

Steps

1. Activate Serrated Biskelion by tapping it, putting a -1/-1 counter on it and Butcher Ghoul.
2. Activate Ashnod's Altar by sacrificing Butcher Ghoul, adding .
3. When Butcher Ghoul dies, its undying ability and Serrated Biskelion trigger.
4. Resolve the Serrated Biskelion trigger, untapping it.
5. Resolve the Butcher Ghoul trigger, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6. When Butcher Ghoul leaves your graveyard, Thran Vigil triggers, putting a +1/+1 counter on Serrated Biskelion.
7. Repeat.

Results