Heartmender + Thran Vigil + Phantom Train

Heartmender

Thran Vigil

Phantom Train

How it works

1. Activate Phantom Train by sacrificing Heartmender.
2. When Heartmender dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Thran Vigil triggers, putting a +1/+1 counter on Heartmender.
4. Resolve the Phantom Train ability.
5. Repeat.

This loop turns a simple sacrifice outlet into an engine of endless rebirth by playing on the interaction between persist and counter-neutralizing mechanics. When you sacrifice Heartmender to Phantom Train, its persist ability normally brings it back with a permanent -1/-1 counter, but Heartmender's own upkeep trigger—or in this active loop, the +1/+1 counter from Thran Vigil—instantly cancels it out. Because Thran Vigil watches for cards leaving your graveyard during your turn, it rewards the constant recycling of Heartmender by steadily pumping your board with infinite +1/+1 counters, death triggers, and enters-the-battlefield value.