Activate Phyrexian Altar by sacrificing Sin.
When Sin dies, it and Verdant Succession trigger.
Resolve the Sin trigger, moving any counters from it onto another creature you control, and then shuffling Sin into your library.
Resolve the Verdant Succession trigger, searching your library for Sin and putting it onto the battlefield.
Repeat.

Infinite LTB

Infinite ETB

Infinite colored mana

Infinite sacrifice triggers

Infinite death triggers

Infinite +1/+1 counters

Sin, Unending Cataclysm

Verdant Succession

Phyrexian Altar

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

Infinite storm count

Infinite mana creatures you control can produce

Infinite untap of all creatures

Infinite commander casts

Infinite +1/+1 counters on a creature

Intruder Alarm

Selvala, Heart of the Wilds

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

Thornbite Staff

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

Aura of Dominion

Combos with "Sin, Unending Cataclysm"