Sin, Unending Cataclysm + Intruder Alarm + Altar of Dementia + Kami of Whispered Hopes

Sin, Unending Cataclysm

Intruder Alarm

Altar of Dementia

Kami of Whispered Hopes

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 plus one due to Kami of Whispered Hopes.
3. When Sin enters, Intruder Alarm triggers, untapping all creatures.
4. Activate Altar of Dementia by sacrificing Sin.
5. Choose to return Sin to the command zone from your graveyard.
6. When Sin dies, it triggers, putting its counters plus an additional +1/+1 counter on Kami of Whispered Hopes.
7. Resolve the Altar of Dementia ability.
8. Activate Kami of Whispered Hopes by tapping it, adding an amount of or equal to its power.
9. Repeat.

This brilliant loop transforms the battlefield into a perpetual-motion engine by exploiting the explosive scaling of Sin, Unending Cataclysm. As Sin enters, it strips counters off your permanents to grow massive, a process supercharged by Kami of Whispered Hopes, which injects extra counters and taps to generate a mountain of colored mana using its own power. Every time Sin drops, Intruder Alarm catches the creature entering and untaps your board, allowing you to feed Sin to Altar of Dementia for a devastating torrent of milling. Finally, sending Sin back to the command zone lets its death trigger pile all of its accumulated power right back onto Kami of Whispered Hopes, leaving you ready to recast your commander and repeat the cycle indefinitely.