Zul Ashur, Lich Lord + Intruder Alarm + Phantom Train

Zul Ashur, Lich Lord

Intruder Alarm

Phantom Train

How it works

1. Activate Zul Ashur by tapping it, targeting a Zombie card in your graveyard.
2. Activate any number of creatures you control by tapping them, adding enough mana to cast the Zombie.
3. Cast the Zombie from your graveyard by paying its mana cost.
4. When the Zombie enters the battlefield, Intruder Alarm triggers, untapping all creatures.
5. Activate Phantom Train by sacrificing the Zombie, putting a +1/+1 counter on Phantom Train.
6. Repeat.

This loop transforms Zul Ashur, Lich Lord into a relentless graveyard necromancer by leveraging Intruder Alarm's static untap trigger every single time a creature enters the battlefield. Once you cast a Zombie from your graveyard using Zul Ashur's tap ability, Intruder Alarm untaps all your creatures—including Zul Ashur and your mana producers—allowing you to feed Phantom Train's sacrifice ability with that newly entered Zombie. By sacrificing the Zombie to Phantom Train, you grow its power with +1/+1 counters while clearing the path to tap Zul Ashur and recast the Zombie all over again for an infinite cascade of enter-the-battlefield and death triggers.