Deal damage to Polyraptor.
Rite of Passage and Polyraptor trigger.
Resolve the Rite of Passage trigger, putting a +1/+1 counter on Polyraptor.
Resolve the Polyraptor trigger, creating a token copy of it.
The Polyraptor token enters the battlefield, triggering Forerunner of the Empire's second ability, dealing 1 damage to each creature.
Rite of Passage triggers for each creature you control, and each Polyraptor you control triggers.
Resolve all Rite of Passage triggers, putting a +1/+1 counter on each creature you control.
Resolve a Polyraptor trigger, creating a token copy of it.
Repeat from step 5.

Infinite +1/+1 counters

Infinite creature tokens

Infinite damage to all creatures

Infinite damage to creatures

Infinite death triggers

Infinite ETB

Infinite LTB

Polyraptor

Forerunner of the Empire

Rite of Passage

Activate the permanent by tapping it, adding {R}.
Activate Pyrohemia by paying {R}, dealing 1 damage to each creature and each player.
Cacophodon and Rite of Passage trigger.
Resolve the Rite of Passage trigger, putting a +1/+1 counter on each creature you control.
Resolve the Cacophodon trigger, untapping the permanent that can produce {R}.
Repeat.

Infinite damage

Near-infinite +1/+1 counters

Cacophodon

Pyrohemia

Deal exactly 1 or 2 damage to Boros Reckoner.
Rite of Passage and Boros Reckoner trigger twice.
Resolve both Rite of Passage triggers, putting two +1/+1 counters on Boros Reckoner.
Resolve the first Boros Recknoer trigger, dealing damage equal to the damage dealt to it to any target.
Resolve the second Boros Reckoner trigger, dealing damage equal to the damage dealt to it to itself.
Repeat from step 2.

Infinite +1/+1 counters on creatures you control with toughness 3 or greater

Wayta, Trainer Prodigy

Boros Reckoner

Activate Fire Ants by tapping it, dealing 1 damage to each other creature without flying.
Rite of Passage triggers for each creature you control that was dealt damage this way, and Cacophodon triggers once.
Resolve all Rite of Passage triggers, putting a +1/+1 counter on each creature you control that was dealt damage.
Resolve the Cacophodon trigger, untapping Fire Ants.
Repeat.

Infinite +1/+1 counters on all creatures you control without flying except Fire Ants

Infinite damage to creatures opponents control without flying

Fire Ants

Cause a Dinosaur to enter the battlefield under your control.
Forerunner of the Empire's second ability triggers, dealing 1 damage to each creature.
Raptor Hatchling triggers, and Rite of Passage triggers for each of your creatures dealt damage this way.
Resolve all Rite of Passage triggers, putting a +1/+1 counter on each creature you control.
Resolve the Raptor Hatchling trigger, creating a 3/3 Dinosaur creature token.
Repeat from step 2.

Raptor Hatchling

Deal exactly 1 or 2 damage to Spitemare.
Rite of Passage and Spitemare trigger twice.
Resolve both Rite of Passage triggers, putting two +1/+1 counters on Spitemare.
Resolve the first Spitemare trigger, dealing damage equal to the damage dealt to it to any target.
Resolve the second Spitemare trigger, dealing damage equal to the damage dealt to it to itself.
Repeat from step 2.

Spitemare

Deal exactly 1 damage to Indoraptor.
Indoraptor, Rite of Passage and Blazing Sunsteel trigger.
Resolve the Rite of Passage trigger, putting a +1/+1 counter on Indoraptor.
Resolve the Indoraptor trigger, causing it to deal damage equal to its power to a random opponent unless they sacrifice a creature.
Resolve the Blazing Sunsteel trigger, dealing 1 damage to Indoraptor.
Repeat from step 2.

Infinite +1/+1 counters on Indoraptor

Indoraptor, the Perfect Hybrid

Blazing Sunsteel

Activate Walking Ballista by removing a +1/+1 counter from it, dealing 1 damage to itself.
Rite of Passage triggers, putting two +1/+1 counters on Walking Ballista.
Repeat an arbitrarily large number of times.
Move to the next turn, removing all damage marked on Walking Ballista.
Activate Walking Ballista by removing a +1/+1 counter from it, dealing 1 damage to any target.
Repeat step 5 as desired.

Hardened Scales

Walking Ballista

Activate the permanent by tapping it, adding {B}.
Activate Pestilence by paying {B}, dealing 1 damage to each creature and each player.
Cacophodon and Rite of Passage trigger.
Resolve the Rite of Passage trigger, putting a +1/+1 counter on each creature you control.
Resolve the Cacophodon trigger, untapping the permanent that can produce {B}.
Repeat.

Pestilence

Deal damage to Vrondiss.
Rite of Passage and Vrondiss trigger.
Resolve the Rite of Passage trigger, putting a +1/+1 counter on Vrondiss.
Resolve the Vrondiss trigger, creating a 5/4 Dragon Spirit creature token.
The Dragon Spirit enters the battlefield, triggering Warstorm Surge, causing the Dragon Spirit to deal damage equal to its power to any target.
The Dragon Spirit triggers, causing you to sacrifice it.
The Dragon dies, triggering Outpost Siege, dealing 1 damage to Vronidss.
Repeat from step 2.

Infinite sacrifice triggers

Vrondiss, Rage of Ancients

Outpost Siege

Warstorm Surge

Deal damage to Vrondiss.
Rite of Passage and Vrondiss trigger.
Resolve the Rite of Passage trigger, putting a +1/+1 counter on Vrondiss.
Resolve the Vrondiss trigger, creating a 5/4 Dragon Spirit creature token.
The Dragon Spirit enters the battlefield, triggering Scourge of Valkas, causing the Dragon Spirit to deal damage equal to the number of Dragons you control to any target.
The Dragon Spirit triggers, causing you to sacrifice it.
The Dragon dies, triggering Outpost Siege, dealing 1 damage to Vronidss.
Repeat from step 2.

Scourge of Valkas

Deal damage to Vrondiss.
Rite of Passage and Vrondiss trigger.
Resolve the Rite of Passage trigger, putting a +1/+1 counter on Vrondiss.
Resolve the Vrondiss trigger, creating a 5/4 Dragon Spirit creature token.
The Dragon Spirit enters the battlefield, triggering Pandemonium, causing the Dragon Spirit to deal damage equal to its power to any target.
The Dragon Spirit triggers, causing you to sacrifice it.
The Dragon dies, triggering Outpost Siege, dealing 1 damage to Vronidss.
Repeat from step 2.

Pandemonium

Activate Walking Ballista by removing a +1/+1 counter from it, dealing 1 damage to itself.
Rite of Passage and Mirrormade trigger, putting two +1/+1 counters on Walking Ballista.
Repeat an arbitrarily large number of times.
Move to the next turn, removing all damage marked on Walking Ballista.
Activate Walking Ballista by removing a +1/+1 counter from it, dealing 1 damage to any target.
Repeat step 5 as desired.

Combos with "Rite of Passage"