Pay {R} to activate Planebound Accomplice putting Chandra, Flamecaller onto the battlefield.
Cloudstone Curio triggers, returning Chandra, Torch of Defiance to your hand.
+1 Chandra, Flamecaller creating 2 3/1 elementals with haste.
Then pay {R} to activate Planebound Accomplice once again, putting Chandra, Torch of Defiance onto the battlefield.
Cloudstone Curio triggers, returning Chandra, Flamecaller to your hand.
+1 Chandra adding {R}{R}.
Repeat.

Infinite creature ETB

Infinite creature tokens with haste

Infinite planeswalker activations

Chandra, Torch of Defiance

Planebound Accomplice

Cloudstone Curio

Chandra, Flamecaller

Pay {R} to activate Planebound Accomplice putting Chandra, Flamecaller onto the battlefield.
Cloudstone Curio triggers, returning Chandra, Novice Pyromancer to your hand.
+1 Chandra, Flamecaller creating 2 elemental tokens with haste.
Then pay {R} to activate Planebound Accomplice once again, putting Chandra, Novice Pyromancer onto the battlefield.
Cloudstone Curio triggers, returning Chandra, Flamecaller to your hand.
-1 Chandra adding {R}{R}.
Repeat.

Chandra, Novice Pyromancer

Activate Chandra's first loyalty ability by putting two loyalty counters on it, creating two 1/1 Elemental creature tokens.
Activate Ashnod's Altar twice by sacrificing the Elementals, adding {C}{C}{C}{C}.
Activate The Chain Veil by paying {4} and tapping it, allowing an extra activation of your planeswalkers' loyalty abilities this turn.
Activate Teferi's first loyalty ability by putting a loyalty counter on it, untapping The Chain Veil and up to other other creature and/or land you control, and causing you to gain 2 life.
Repeat.

Infinite activations of most planeswalkers

Infinite death triggers

Infinite lifegain

Infinite lifegain triggers

Infinite creature LTB

Infinite mana creatures you control can produce

Infinite mana lands you control can produce

Infinite mana permanents you control can produce

Infinite creature sacrifice triggers

Infinite untap of creatures and lands you control

The Chain Veil

Ashnod's Altar

Teferi, Who Slows the Sunset

Activate Chandra's first loyalty ability by putting two loyalty counters on it, creating two 1/1 Elemental creature tokens.
Activate Ashnod's Altar twice by sacrificing the Elementals, adding {C}{C}{C}{C}.
Activate The Chain Veil by paying {4} and tapping it, allowing an extra activation of your planeswalkers' loyalty abilities this turn.
Activate Ral Zarek's first loyalty ability by putting a loyalty counter on it, untapping The Chain Veil.
Repeat.

Ral Zarek

Activate Chandra's first loyalty ability by putting a loyalty counter on it, creating two 3/1 Elemental creature tokens with haste.
When the Elementals enter the battlefield, Intruder Alarm triggers twice.
Resolve the first trigger, untapping all creatures.
Activate Aphetto Alchemist by tapping it, untapping The Chain Veil.
Resolve the second Intruder Alarm trigger, untapping all creatures.
Activate Aphetto Alchemist by tapping it, untapping target artifact or creature.
Activate Ashnod's Altar twice by sacrificing the two Elemental tokens, adding {C}{C}{C}{C}.
Activate The Chain Veil by paying {4} and tapping it, allowing you an additional activation of your planeswalkers' loyalty abilities this turn.
Repeat.

Infinite mana artifacts you control can produce

Infinite untap of creatures

Infinite untap of artifacts you control

Aphetto Alchemist

Intruder Alarm

Activate Chandra's first loyalty ability by putting two loyalty counters on it, creating two 1/1 Elemental creature tokens.
Activate Ashnod's Altar twice by sacrificing the Elementals, adding {C}{C}{C}{C}.
Activate The Chain Veil by paying {4} and tapping it, allowing an extra activation of your planeswalkers' loyalty abilities this turn.
Activate Kiora by removing zero loyalty counters from it, untapping The Chain Veil.
Repeat.

Carth the Lion

Kiora, Behemoth Beckoner

Combos with "Chandra, Flamecaller"