Sin, Unending Cataclysm + Aura of Dominion + Phyrexian Altar + Selvala, Heart of the Wilds

Sin, Unending Cataclysm

Aura of Dominion

Phyrexian Altar

Selvala, Heart of the Wilds

How it works

1. Cast Sin either from your hand or command zone by paying 5 plus commander tax if applicable.
2. As Sin enters, remove all counters from all artifacts, enchantments and creatures you control, putting twice that many +1/+1 counters on Sin.
3. Activate Selvala by paying and tapping it, adding at least plus an additional X equal to Sin's power minus 3.
4. Activate Aura of Dominion by paying 1 and tapping Sin, untapping Selvala.
5. Activate Phyrexian Altar by sacrificing Sin, adding 1.
6. Choose to return Sin to the command zone from your graveyard.
7. When Sin dies, it triggers, putting its counters on Selvala.
8. Repeat.

This loop turns Sin, Unending Cataclysm into an explosive, recurring engine by leveraging its massive entry-stats to fuel an entire ecosystem. As Sin enters, its replacement effect strips counters from your board to stack up a colossal pool of +1/+1 counters, which immediately makes its power dwarf everything else for Selvala, Heart of the Wilds. Tapping Selvala converts that massive power into a flood of colored mana, while Aura of Dominion uses a fraction of that mana and a tap of Sin to untap Selvala, keeping the chain moving. Finally, sacrificing Sin to Phyrexian Altar generates the final sliver of mana and sends your commander back to the zone to be recast, letting you repeat the entire spectacle indefinitely.