Ulamog's Dreadsire + Thornbite Staff + Phantom Train

Ulamog's Dreadsire

Thornbite Staff

Phantom Train

How it works

1. Activate Ulamog's Dreadsire by tapping it, creating a 10/10 Eldrazi creature tokens.
2. Activate Phantom Train by sacrificing the Eldrazi token.
3. When the Eldrazi token dies, Ulamog's Dreadsire triggers, untapping Ulamog's Dreadsire.
4. Resolve the Phantom Train ability
5. Repeat.

This elegant loop transforms the raw power of Ulamog's Dreadsire into an infinite engine, relying on Thornbite Staff to weaponize the natural cycle of life and death. By using Thornbite Staff's granted untap ability triggered by things dying, every time Phantom Train consumes the Eldrazi token you just created, Ulamog's Dreadsire springs back to life, ready to tap again for another 10/10 token. Meanwhile, Phantom Train gratefully accepts each sacrificed Eldrazi token to grow indefinitely with +1/+1 counters, generating boundless sacrifices, enter-the-battlefield triggers, and death triggers to overwhelm your opponents.