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

Heidar, Rimewind Master

Intruder Alarm

Dual Nature

Ashnod's Altar

Crimson Kobolds

How it works

1. Cast Crimson Kobolds by paying 0.
2. When Crimson Kobolds 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 Crimson Kobolds.
5. Activate Ashnod's Altar by sacrificing the Crimson Kobolds token, adding CC.
6. Activate Heidar by paying 2 and tapping it, returning Crimson Kobolds to your hand from the battlefield.
7. Dual Nature's second ability triggers, exiling nothing.
8. Repeat.

This intricate loop starts by casting Crimson Kobolds for free, which immediately triggers Intruder Alarm to untap your creatures and Dual Nature to spawn a matching token copy. With your board primed, Ashnod's Altar converts that token into a pair of colorless mana to help fund Heidar, Rimewind Master's activation. Tapping Heidar, Rimewind Master returns the original Crimson Kobolds back to your hand, allowing you to replay it, refresh the entire loop, and harvest infinite mana, enters-the-battlefield triggers, and untaps.