Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Sin, Unending Cataclysm + Thermopod

WUBRG identity

Commander legal

The 3 combo pieces

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight
• Sin, Unending Cataclysm
• Thermopod

How to execute it

1. Activate Thermopod by sacrificing it
2. When Thermopod dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Activate Thermopod by sacrificing Sin.
4. When Sin dies, it triggers twice.
5. Resolve the first trigger, returning Sin from your graveyard to the battlefield with a -1/-1 counter on it. As Sin enters, remove the -1/-1 counter from Thermopod, causing Sin to enter with a +1/+1 counter on it instead.
6. Resolve the second Sin trigger, putting the counters it had on it when it was sacrificed onto a creature you control and failing to shuffle it into your library as it's no longer in your graveyard.
7. Repeat.

What the combo produces

• Infinite +1/+1 counters on creatures you control
• Infinite creature LTB
• Infinite death triggers
• Infinite ETB
• Infinite red mana
• Infinite sacrifice triggers