Cast Changeling Hero by paying its mana cost.
When Changeling Hero enters the battlefield, its champion ability and Molten Echoes triggers.
Resolve the Molten Echoes trigger, creating a token copy of Changeling Hero with haste.
When the Changeling Hero token enters the battlefiled, its champion ability triggers, exiling the nontoken Changeling Hero until the token Changeling Hero leaves the battlefield.
Resolve the champion ability from step 2, exiling the token Changeling Hero.
The token Changeling Hero leaves the battlefield, returning the nontoken Changeling Hero from exile to the battlefield.
Repeat from step 2.

Infinite LTB

Infinite ETB

Molten Echoes

Changeling Hero

Cast Deathbellow War Cry by paying {5}{R}{R}{R}, putting Changeling Berserker, Changeling Hero, and Changeling Titan onto the battlefield.
Changeling Hero, Changeling Titan, and Changeling Berserker enters the battlefield triggers.
Resolve Changeling Hero triggers by championing Changeling Titan.
Resolve Changeling Titan triggers, does nothing.
Resolve Changeling Berserker triggers by championing Changeling Hero.
Changeling Titan enters the battlefield triggers.
Resolve Changeling Titan triggers, championing Changeling Berserker.
Changeling Hero enters the battlefield triggers.
Repeat from step 3.

Deathbellow War Cry

Changeling Berserker

Changeling Titan

Cast Changeling Hero by paying {4}{W}.
Changeling Hero enters the battlefield, championing Karmic Guide.
Activate Ashnod's Altar by sacrificing Changeling Hero, adding {C}{C}.
Changeling Hero dies, causing Karmic Guide to return to the battlefield from exile.
Karmic Guide enters the battlefield, returning Changeling Hero from your graveyard to the battlefield.
Repeat from step 2.

Infinite colorless mana

Infinite death triggers

Infinite sacrifice triggers

Karmic Guide

Ashnod's Altar

Cast Yannik by paying {2}{G}{W} and commander tax, if applicable.
Yannik enters the battlefield, exiling Changeling Hero and distributing a number of +1/+1 counters equal to Changeling Hero's power among creatures you control.
The creature that was championed by Changeling Hero returns to the battlefield from exile.
Cast Fiend Hunter by paying {1}{W}{W}.
Fiend Hunter enters the battlefield, exiling Yannik.
Changeling Hero returns to the battlefield from exile, championing Fiend Hunter.
Fiend Hunter leaves the battlefield, returning Yannik to the battlefield from exile.
Yannik enters the battlefield, exiling Changeling Hero and distributing a number of +1/+1 counters equal to Changeling Hero's power among creatures you control.
Changeling Hero leaves the battlefield, returning Fiend Hunter to the battlefield from exile.
Repeat from step 5.

Infinite +1/+1 counters on creatures you control

Yannik, Scavenging Sentinel

Fiend Hunter

Cast Changeling Hero by paying {4}{W}.
When Changeling Hero enters the battlefield, its champion ability and Dual Nature's first ability trigger.
Resolve the Dual Nature trigger, creating a token copy of Changeling Hero.
When the Changeling Hero token enters the battlefield, its champion ability triggers, exiling the nontoken Changeling Hero.
Dual Nature's second ability triggers, exiling the Changeling Hero token.
When the Changeling Hero token leaves the battlefield, the nontoken Changeling Hero is returned to the battlefield from exile.
Repeat from step 2.
If you control additional creatures you wish to blink, you may resolve the Changeling Hero trigger in step 2 to exile them, and then proceed with the combo.

Infinite blinking

Dual Nature

Cast Changeling Hero by paying {4}{W}.
Changeling Hero enters the battlefield, championing Bloodline Necromancer.
Activate Viscera Seer by sacrificing Changeling Hero.
Changeling Hero dies, causing Bloodline Necromancer to return to the battlefield from exile.
Bloodline Necromancer enters the battlefield, returning Changeling Hero from your graveyard to the battlefield.
Repeat from step 2.
Resolve all Viscera Seer abilities, causing you to scry 1 an infinite number of times.

Infinite scry 1

Bloodline Necromancer

Viscera Seer

Cast Changeling Hero by paying {3}{R}.
When Changeling Hero enters the battlefield, it and Terror of the Peaks trigger.
Resolve the Changeling Hero trigger, exiling Bladewing until Changeling Hero leaves the battlefield.
Resolve the Terror of the Peaks trigger, dealing damage to Changeling Hero equal to Changeling Hero's power.
Changeling Hero dies as a state-based action due to having 0 or less toughness.
When Changeling Hero dies, it triggers, returning Bladewing from exile to the battlefield.
When Bladewing enters the battlefield, it and Terror of the Peaks trigger.
Resolve the Terror of the Peaks trigger, dealing damage equal to Bladewing's power to any target.
Resolve the Bladewing trigger, returning Changeling Hero from your graveyard to the battlefield.
Repeat from step 2.

Infinite damage

Bladewing the Risen

Terror of the Peaks

Cast Changeling Hero by paying {4}{W}.
Changeling Hero enters the battlefield, triggering its champion ability and Inalla.
Resolve the Inalla trigger, causing you to pay {1} to create a token copy of Changeling Hero with haste.
The token Changeling Hero enters the battlefield, championing the nontoken Changeling Hero.
The nontoken Changeling Hero leaves the battlefield, returning nothing from exile to the battlefield.
Resolve the nontoken Changeling Hero trigger from step 2, choosing not to exile anything.
Activate Ashnod's Altar by sacrificing the Mistbind Clique token, adding at least one mana.
The Changeling Hero token leaves the battlefield, returning the nontoken Changeling Hero from exile to the battlefield.
Repeat from step 2.

Combos with "Changeling Hero"