Infernal Vessel + Valkyrie's Call + Phantom Train

Infernal Vessel

Valkyrie's Call

Phantom Train

How it works

1. Activate Phantom Train by sacrificing Infernal Vessel.
2. When Infernal Vessel dies, it triggers, returning itself from your graveyard to the battlefield as a Demon in addition to its other types.
3. Resolve the Phantom Train ability.
4. Activate Phantom Train by sacrificing Infernal Vessel.
5. When Infernal Vessel dies, Valkyrie's Call triggers, returning Infernal Vessel from your graveyard to the battlefield as an Angel in additional to its other types.
6. Resolve the Phantom Train ability.
7. Repeat.

This clever loop relies on overlapping continuous replacement effects to continuously recycle Infernal Vessel through the graveyard. When you sacrifice Infernal Vessel to Phantom Train, both its own death trigger and Valkyrie's Call are waiting to return it, allowing you to alternate whether it comes back as a Demon or an Angel on each iteration. Meanwhile, Phantom Train happily accepts each sacrifice to pump itself up with infinite +1/+1 counters while generating endless sacrifice, entry, and death triggers.