Deal damage to an opponent.
Quest for Pure Flame triggers, putting a quest counter on itself.
All Will Be One triggers, dealing 1 damage to an opponent.
Repeat from step 2.

Infinite damage

All Will Be One

Quest for Pure Flame

Sacrifice Quest for the Pure Flame.
Tap Heartless Hidetsugu to deal opponent life equal to their lifetotal.

Deal damage equal to each opponents' life total to them

Heartless Hidetsugu

Platinum Angel

Glacial Chasm

Platinum Emperion

Activate Quest for Pure Flame by removing four quest counters from it and sacrificing it.
Activate Heartless Hidetsugu by tapping it, dealing damage to each opponent equal to half their life total, rounded down, times 2, and dealing no damage to you due to Pariah's Shield.

Near-infinite damage

Pariah's Shield

Activate Quest for Pure Flame by removing four quest counters from it and sacrificing it, doubling the amount of damage sources you control deal this turn.
Activate Walking Ballista's second ability by removing a +1/+1 counter from it, putting two +1/+1 counters on it due to Vigor.
Activate Walking Ballista's second ability by removing a +1/+1 counter from it, dealing 2 damage to any target.
Repeat from step 2 as desired.

Infinite +1/+1 counters

Vigor

Walking Ballista

Activate Duchess by paying {1} and removing a quest counter from a permanent you control, creating a Junk token.
When the Junk enters, Reckless Fireweaver triggers, dealing 1 damage to each opponent.
Quest for Pure Flame triggers, putting a quest counter on it.
Activate the Junk by tapping and sacrificing it.
Rose triggers, adding {R}.
Resolve the Junk's ability, exiling the top card of your library with the ability to play it until end of turn.
Repeat.

Exile your library with the ability to play the exiled cards until end of turn

Duchess, Wayward Tavernkeep

Rose, Cutthroat Raider

Reckless Fireweaver

Activate Duchess by paying {1} and removing a quest counter from a permanent you control, creating a Junk token.
When the Junk enters, Reckless Fireweaver triggers, dealing 1 damage to each opponent.
Quest for Pure Flame triggers, putting a quest counter on it.
Activate the Junk by tapping and sacrificing it.
Crime Novelist triggers, adding {R} and putting a +1/+1 counter on it.
Resolve the Junk's ability, exiling the top card of your library with the ability to play it until end of turn.
Repeat.

Infinite +1/+1 counters on a creature

Crime Novelist

Activate Quest for Pure Flame by removing four quest counters from it and sacrificing it, doubling the amount of damage sources you control deal this turn.
Activate Triskelion by removing a +1/+1 counter from it, putting two +1/+1 counters on it due to Vigor.
Activate Triskelion by removing a +1/+1 counter from it, dealing 2 damage to any target.
Repeat from step 2 as desired.

Triskelion

Activate Deathless Angel twice by paying {W}{W}{W}{W}, giving two creatures an opponent controls indestructible until end of turn.
Deal noncombat damage to one of the indestructible creatures, dealing an increased amount of damage instead due to Quest for Pure Flame.
Toralf triggers, dealing an amount of damage over the excess damage to the second indestructible creature due to Quest for Pure Flame.
Toralf triggers, dealing an amount of damage over the excess damage to the first indestructible creature due to Quest for Pure Flame.
Repeat from step 3 an arbitrarily large number of times.
Resolve a Toralf trigger, dealing infinite damage to any target.

Infinite damage to any target

Toralf, God of Fury // Toralf's Hammer

Deathless Angel

Activate Quest for Pure Flame by removing four quest counters from it and sacrificing it, doubling the damage sources you control will deal this turn.
Activate Anti-Venom using Walking Ballista's ability by removing a +1/+1 counter from it, targeting itself and putting two +1/+1 counters on it due to its replacement effect and Quest for Pure Flame.
Activate Anti-Venom using Walking Ballista's ability by removing a +1/+1 counter from it, dealing 1 damage to any target.
Repeat from step 2.

Anti-Venom, Horrifying Healer

Agatha's Soul Cauldron

Give Tephraderm indestructible, if needed.
Activate Quest for Pure Flame by removing four quest counters from it and sacrificing it, doubling the damage sources you control deal this turn.
Cast Star of Extinction by paying {5}{R}{R}.
Hive Mind triggers, causing each opponent to copy Star of Extinction.
Resolve an opponent's Star of Extinction, destroying a land and dealing 20 damage to each creature and planeswalker.
Tephraderm's second ability triggers, dealing 40 damage to the opponent who controlled the Star of Extinction copy due to Quest for Pure Flame.
Repeat from step 5 for each remaining Star of Extinction until each opponent loses the game.

Tephraderm

Hive Mind

Star of Extinction

Give Walking Ballista lifelink, if needed.
If Walking Ballista has less than two +1/+1 counters on it, activate Unspeakable Symbol by paying 3 life, putting a +1/+1 counter on Walking Ballista.
Activate Walking Ballista's second ability by removing a +1/+1 counter from it, dealing 4 damage to an opponent or a permanent an opponent controls, and causing you to gain 4 life.
Repeat from step 2.

Infinite lifegain triggers

Infinite lifegain

Unspeakable Symbol

Far Fortune, End Boss

Activate Quest for Pure Flame by removing four quest counters from it and sacrificing it, doubling the amount of damage sources you control deal this turn.
Activate Deathbringer Thoctar by removing a +1/+1 counter from it, putting two +1/+1 counters on it due to Vigor.
Activate Deathbringer Thoctar by removing a +1/+1 counter from it, dealing 2 damage to any target.
Repeat from step 2 as desired.

Combos with "Quest for Pure Flame"