Activate Diamond Lion by tapping it, discarding your hand, and sacrificing it, adding {R}{R}{R} or {W}{W}{W}.
Cast a copy of Pack a Punch from exile by paying {1}{W}{R}, unpreparing Kirol.
When you cast that spell, Forum Necroscribe triggers, returning Diamond Lion from your graveyard to the battlefield.
When Diamond Lion leaves your graveyard, Kirol triggers, becoming prepared.
Pack a Punch resolves, causing you to mill a card, put two +1/+1 counters onto its target, and give it trample until end of turn.
Repeat.

Infinite artifact ETB

Infinite artifact LTB

Infinite magecraft triggers

Infinite self-mill

Infinite storm count

Infinite +1/+1 counters on most creatures you control

Infinite creature ETB

Infinite creature LTB

Infinite death triggers

Infinite creature sacrifice triggers

Haste Enabler

Kirol, History Buff // Pack a Punch

Diamond Lion

Forum Necroscribe

Cast Traitorous Greed by paying {3}{R}.
Forum Necroscribe triggers, returning Living Lightning from your graveyard to the battlefield.
Resolve Traitorous Greed, untapping Priest of the Forgotten Gods, giving it haste until end of turn, and adding {R}{R}.
Activate Priest of the Forgotten Gods by tapping it, sacrificing Living Lightning and any creature not part of the combo.
When Living Lightning dies, it and Bridge from Below triggers.
Resolve the Living Lightning trigger, returning Traitorous Greed from your graveyard to your hand.
Resolve the Bridge from Below trigger, creating a creature token.
Resolve the Priest of the Forgotten Gods ability, causing any number of opponents to sacrifice a creature and lose 2 life, adding {B}{B}, and drawing a card.
Repeat, sacrificing the newly created token in step 4 instead of the additional creature.

Each opponent sacrifices nearly infinite creatures

Infinite card draw

Infinite draw triggers

Near-infinite creature ETB

Near-infinite creature LTB

Near-infinite death triggers

Near-infinite lifeloss

Near-infinite creature sacrifice triggers

Near-infinite storm count

Priest of Forgotten Gods

Traitorous Greed

Bridge from Below

Living Lightning

Activate Composite Golem by sacrificing it, adding {W}{U}{B}{R}{G}.
Cast a copy of Pack a Punch from exile by paying {1}{R}{W}, unpreparing Kirol.
When you cast that spell, Forum Necroscribe triggers, returning Composite Golem from your graveyard to the battlefield.
When Composite Golem leaves the battlefield, Kirol triggers, becoming prepared.
Resolve the copy of Pack a Punch, milling a card, putting two +1/+1 counters on the target, and giving it trample until end of turn.
Repeat.

Infinite black mana

Infinite blue mana

Infinite green mana

Composite Golem

Combos with "Forum Necroscribe"