Éomer, Marshal of Rohan + Altaïr Ibn-La'Ahad + Maskwood Nexus + Phantom Train

Éomer, Marshal of Rohan

Altaïr Ibn-La'Ahad

Maskwood Nexus

Phantom Train

How it works

1. Declare Altaïr as an attacker. Altaïr triggers, exiling Éomer from your graveyard with a memory counter on it, and then creating a tapped and attacking token copy of each card you own that is exiled with a memory counter on it.
2. Activate Phantom Train by sacrificing another legendary creature token except Éomer.
3. When the creature dies, Éomer triggers, untapping all creatures you control and causing you to get an additional combat phase after this one.
4. Resolve the Phantom Train ability.
5. Repeat during each combat phase.

This looping engine relies on Maskwood Nexus to turn every creature on your battlefield into an Assassin, seamlessly feeding the sacrifice requirements of Phantom Train. When you declare Altaïr Ibn-La'Ahad as an attacker, its ability exiles Éomer, Marshal of Rohan from your graveyard and spins up a token copy of it that enters the fray already attacking. You then sacrifice one of your legendary creature tokens to power up Phantom Train, which immediately triggers the freshly manifested Éomer; its ability untaps your entire board and grants you an additional combat phase. Because Maskwood Nexus ensures all your creature tokens carry the legendary Assassin pedigree, you can repeat this cycle endlessly to generate infinite combat phases, deaths, and massive +1/+1 counters on your Phantom Train.