Omarthis, Ghostfire Initiate + Mirage Mirror + Coat of Arms + Mirror Gallery

Omarthis, Ghostfire Initiate

Mirage Mirror

Coat of Arms

Mirror Gallery

How it works

1. Put a +1/+1 counter on a colorless creature you control.
2. Omarthis's first triggered ability triggers.
3. In response, activate Mirage Mirror by paying 2, causing it to become a copy of Omarthis until end of turn.
4. Resolve the Omarthis trigger, putting a +1/+1 counter on itself.
5. Mirage Mirror triggers, putting a +1/+1 counter on itself.
6. Omarthis triggers, putting a +1/+1 counter on itself.
7. Repeat from step 5 any number of times.
8. End the loop by declining to place a +1/+1 counter on a creature.
9. Warning: Omarthis's last ability can increase the risk of losing by drawing from an empty library if you place enough counters on them.

This delightfully recursive loop hinges on Mirage Mirror temporarily mimicking Omarthis, Ghostfire Initiate so that they continuously trigger one another's growth whenever a counter is placed. Because Mirror Gallery is on the battlefield, you don't have to worry about the legend rule putting your copied artifact into the graveyard when it turns into Omarthis. Meanwhile, Coat of Arms supercharges the board by passively granting all these growing, shared-type creatures a massive power and toughness boost for every other creature in play.