Koll, the Forgemaster + Demonmail Hauberk + Ornithopter + Phyrexian Walker

Koll, the Forgemaster

Demonmail Hauberk

Ornithopter

Phyrexian Walker

How it works

1. Activate Demonmail Hauberk's equip ability by sacrificing Ornithopter, targeting Phyrexian Walker.
2. When Ornithopter dies, Koll triggers, returning Ornithopter from your graveyard to your hand.
3. Resolve the Demonmail Hauberk ability, attaching it to Phyrexian Walker.
4. Cast Ornithopter by paying 0.
5. Activate Demonmail Hauberk's equip ability by sacrificing Phyrexian Walker, targeting Ornithopter.
6. When Phyrexian Walker dies, Koll triggers, returning Phyrexian Walker from your graveyard to your hand.
7. Resolve the Demonmail Hauberk ability, attaching it to Ornithopter.
8. Cast Phyrexian Walker by paying 0.
9. Repeat.

This ingenious loop turns Demonmail Hauberk into a zero-cost recycling engine by playing on the interaction between free casting costs and graveyard triggers. With Koll, the Forgemaster granting a recursive safety net whenever an equipped creature dies, you can endlessly sacrifice your free artifact creatures—alternating back and forth between Ornithopter and Phyrexian Walker—to pay for the Hauberk's equip cost. Because both creatures cost zero mana to recast, every iteration resets the board without costing a single drop of mana, yielding infinite sacrifices, deaths, and storm count.