Cast Felidar Guardian by paying {3}{W}.
When Felidar Guardian enters the battlefield, it triggers, targeting Angel of Indemnity.
Holding priority, activate Ashnod's Altar by sacrificing Felidar Guardian, adding {2}.
Resolve the Felidar Guardian ability, blinking Angel of Indemnity.
When Angel of Indemnity enters the battlefield, it triggers, returning Felidar Guardian from your graveyard to the battlefield.
Repeat from step 2.

Infinite LTB

Infinite ETB

Infinite sacrifice triggers

Infinite death triggers

Infinite colorless mana

Ashnod's Altar

Felidar Guardian

Angel of Indemnity

Cast Fiend Hunter by paying its mana cost.
When Fiend Hunter enters, its first ability triggers, exiling Angel of Indemnity.
Activate Altar of Dementia by sacrificing Fiend Hunter.
When Fiend Hunter dies, its second ability triggers, returning Angel of Indemnity from exile to the battlefield.
When Angel of Indemnity enters, it triggers, returning Fiend Hunter from your graveyard to the battlefield.
When Fiend Hunter enters, its first ability triggers, exiling Angel of Indemnity.
Resolve the Altar of Dementia ability.
Repeat from step 3.

Infinite mill

Infinite self-mill

Altar of Dementia

Fiend Hunter

Activate Saffi by sacrificing it, targeting Angel of Indemnity
Activate Altar of Dementia by sacrificing Angel of Indemnity
When Angel of Indemnity dies, Saffi triggers, returning Angel of Indemnity from your graveyard to the battlefield.
When Angel of Indemnity enters, it triggers, returning Saffi from your graveyard to the battlefield.
Resolve the Altar of Dementia ability.
Repeat.

Saffi Eriksdotter

If Aminatou has two or more loyalty counters on it, activate Heart of Kiran by removing a loyalty counter from Aminatou, causing Heart of Kiran to become an artifact creature until end of turn.
Repeat step 1 until Aminatou has one loyalty counter on it.
Activate Aminatou's second loyalty ability by removing a loyalty counter from it, targeting Angel of Indemnity.
Aminatou is put into your graveyard as a state-based action due to having zero loyalty.
Resolve the Aminatou ability, blinking Angel of Indemnity.
When Angel of Indemnity enters the battlefield, it triggers, returning Aminatou from your graveyard to the battlefield.
Repeat.

Aminatou, the Fateshifter

Heart of Kiran

Activate Ashnod's Altar by sacrificing the creature with Deathrender attached, adding {C}{C}.
When the creature dies, Deathrender triggers, putting Angel of Indemnity from your hand onto the battlefield.
When Angel of Indemnity enters the battlefield, it and Cloudstone Curio trigger.
Resolve the Cloudstone Curio trigger, choosing to return nothing to your hand from the battlefield.
Resolve the Angel of Indemnity trigger, returning any nonartifact creature card from your graveyard to the battlefield.
When the creature enters the battlefield, Cloudstone Curio triggers, returning Angel of Indemnity from the battlefield to your hand.
Activate Deathrender's equip ability by paying {2}, attaching it to the creature.
Repeat.

Combos with "Angel of Indemnity"