Requires

Tayam, Luminous Enigma must be on the battlefield. Sengir, the Dark Baron must be on the battlefield. Ashnod's Altar must be on the battlefield. Strangleroot Geist must be on the battlefield. Strangleroot Geist does not have a +1/+1 counter on it. Mana needed:

Steps

1. Activate Ashnod's Altar by sacrificing Strangleroot Geist, adding .
2. When Strangleroot Geist dies, its undying ability and Sengir's first ability trigger.
3. Resolve the Strangleroot Geist trigger, returning it from your graveyard to the battlefield with a +1/+1 counter and a vigilance counter on it.
4. Resolve the Sengir trigger, putting two +1/+1 counters on Sengir.
5. Activate Tayam by paying , removing a +1/+1 counter from Sengir, and both counters from Strangleroot Geist.
6. Holding priority, activate Ashnod's Altar by sacrificing Strangleroot Geist, adding .
7. Repeat steps 2-4 one additional time.
8. Activate Ashnod's Altar by sacrificing Strangleroot Geist, adding .
9. Resolve Tayam's ability from step 5, causing you to mill three cards and returning Strangleroot Geist from your graveyard to the battlefield.
10. Repeat.

Results