Cast Body of Research by paying {G}{G}{G}{U}{U}{U}, creating a 0/0 Fractal creature token and putting a number of +1/+1 counters on it equal to your deck size.
Cast Sin either from your hand or from the command zone by paying {5}{G}{U} plus commander tax if applicable. As it enters, remove all the counters from the Fractal and put twice that many +1/+1 counters on Sin.
Kill Sin. When it dies, it second ability triggers, putting its counters on Sage of Hours and shuffling Sin into your library.
Activate Sage of Hours by removing all +1/+1 counters from it, causing you to get an extra turn for each five +1/+1 counters removed from it.

Lock

Near-infinite turns

Sin, Unending Cataclysm

Body of Research

Sage of Hours

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 creature LTB

Infinite creature ETB

Infinite colored mana

Infinite creature sacrifice triggers

Infinite death triggers

Infinite +1/+1 counters on creatures you control

Verdant Succession

Phyrexian Altar

Activate Shilgengar by sacrificing the additional creature.
When the creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Resolve the Shilgengar ability.
Activate Shilgengar by sacrificing Sin.
When Sin dies, it triggers twice.
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 the creature sacrificed in step 1, causing Sin to enter with a +1/+1 counter on it instead.
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.
Resolve the Shilgengar ability from step 4.
Repeat.

Infinite artifact tokens

Infinite Blood tokens

Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight

Shilgengar, Sire of Famine

Activate Ashnod's Altar by sacrificing Sin, adding {C}{C}.
When Sin dies, it, Heirloom Blade and Deathrender trigger.
Resolve the Sin trigger, shuffling it into your library.
Resolve the Heirloom Blade trigger, causing you to reveal cards from the top of your library until you reveal a creature that shares a card type with Sin and put it into your hand
Resolve the Deathrender trigger, putting the creature from your hand onto the battlefield and attaching Deathrender to it.
Activate Heirloom Blade's equip ability by paying {1}, attaching it to the creature.
Repeat.

Infinite colorless mana

Deathrender

Heirloom Blade

Ashnod's 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 Altar of Dementia by sacrificing Sin.
Choose to return Sin to the command zone from your graveyard.
When Sin dies, it triggers, putting its counters on Selvala.
Resolve the Altar of Dementia ability.
Repeat.

Infinite mill

Infinite self-mill

Infinite storm count

Infinite mana creatures you control can produce

Infinite untap of creatures

Infinite commander casts

Infinite +1/+1 counters on a creature

Intruder Alarm

Altar of Dementia

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"