Heidar, Rimewind Master + Intruder Alarm + Dual Nature + Ashnod's Altar + Kobolds of Kher Keep

Heidar, Rimewind Master

Intruder Alarm

Dual Nature

Ashnod's Altar

Kobolds of Kher Keep

How it works

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