Koll, the Forgemaster + Demonmail Hauberk + Crimson Kobolds + Phyrexian Walker

Koll, the Forgemaster

Demonmail Hauberk

Crimson Kobolds

Phyrexian Walker

How it works

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

This ingenious loop turns zero-mana creatures into a perpetual sacrifice engine by using Demonmail Hauberk's alternate equip cost as a built-in sacrifice outlet. Since both Crimson Kobolds and Phyrexian Walker cost zero mana to cast, you can endlessly alternate sacrificing one to equip the Hauberk to the other. Meanwhile, Koll, the Forgemaster keeps the entire chain moving by watching for the equipped creatures to die and immediately returning them straight to your hand for another round.