Zirda, the Dawnwaker + Stonybrook Schoolmaster + Paradise Mantle + Umbral Mantle

Zirda, the Dawnwaker

Stonybrook Schoolmaster

Paradise Mantle

Umbral Mantle

How it works

1. Activate Stonybrook Schoolmaster by tapping it, adding 1.
2. Stonybrook Schoolmaster triggers, creating a 1/1 Merfolk Wizard creature token.
3. Activate Stonybrook Schoolmaster by paying 1 and untapping it, giving it +2/+2 until end of turn.
4. Repeat.

This elegant engine turns a simple Merfolk into an infinite army by looping mana generation, untaps, and token creation into a self-sustaining loop. Paradise Mantle grants Stonybrook Schoolmaster the ability to tap for mana, which simultaneously triggers its own token production and helps fund the process. Meanwhile, Umbral Mantle provides the untap mechanism needed to reset the schoolmaster, a cost heavily discounted by Zirda, the Dawnwaker's passive ability reduction down to just a single mana.