Tenacious Dead + Pitiless Plunderer + Skittering Precursor + Phantom Train

Tenacious Dead

Pitiless Plunderer

Skittering Precursor

Phantom Train

How it works

1. Activate Phantom Train by sacrificing Tenacious Dead.
2. When Tenacious Dead dies, it, Skittering Precursor, and Pitiless Plunderer trigger.
3. Resolve the Pitiless Plunderer trigger, creating a Treasure token.
4. Resolve the Skittering Precursor trigger, creating a creature token.
5. In response to the remaining trigger, activate Phantom Train by sacrificing the creature token.
6. When the creature token dies, Pitiless Plunderer triggers, creating a Treasure token.
7. Resolve the Phantom Train ability from step 5.
8. Activate two Treasure tokens by tapping and sacrificing them, adding .
9. Resolve the Tenacious Dead trigger, paying 1 to return it to the battlefield from your graveyard.
10. Resolve the Phantom Train ability from step 1.
11. Repeat.