Yarus, Roar of the Old Gods + Master of the Veil + Phantom Train

Yarus, Roar of the Old Gods

Master of the Veil

Phantom Train

How it works

1. Activate Phantom Train by sacrificing Master of the Veil.
2. When Master of the Veil dies, Yarus' second ability triggers, returning Master of the Veil from your graveyard to the battlefield face down, then turning it face up.
3. Master of the Veil triggers, turning itself face down.
4. Resolve the Phantom Train ability
5. Repeat.

This clever loop begins by sacrificing Master of the Veil to Phantom Train, which conveniently puts a +1/+1 counter on the train and animates it. As soon as Master of the Veil dies, Yarus, Roar of the Old Gods steps in with its recursion trigger, bringing Master of the Veil right back to the battlefield face down and immediately flipping it face up. That face-up transition triggers Master of the Veil's own ability, allowing you to turn it back face down so it's ready to be sacrificed to Phantom Train all over again.