Heidar, Rimewind Master + Intruder Alarm + Dual Nature + Ashnod's Altar + Memnite

Heidar, Rimewind Master

Intruder Alarm

Dual Nature

Ashnod's Altar

Memnite

How it works

1. Cast Memnite by paying 0.
2. When Memnite enters the battlefield, Intruder Alarm and Dual Nature's first ability triggers.
3. Resolve the Intruder Alarm trigger, untapping all creatures.
4. Resolve the Dual Nature trigger, creating a token copy of Memnite.
5. Activate Ashnod's Altar by sacrificing the Memnite token, adding CC.
6. Activate Heidar by paying 2 and tapping it, returning Memnite to your hand from the battlefield.
7. Dual Nature's second ability triggers, exiling nothing.
8. Repeat.

This loop transforms the free, zero-mana casting cost of Memnite into an engine for infinite mana and triggers. Every time Memnite enters the battlefield, Intruder Alarm untaps your creatures—including Heidar, Rimewind Master, whose snow-activated ability relies on those untaps to continually return the original Memnite to your hand. Meanwhile, Dual Nature ensures a token copy is created on entry, providing ready fodder for Ashnod's Altar to sacrifice for the colorless mana needed to fund Heidar, Rimewind Master's bounce ability.