Activate Altar of Dementia by sacrificing Fiend Hunter.
When Fiend Hunter dies, its second ability triggers, returning Hero of the Dunes to the battlefield from exile.
When Hero of the Dunes enters the battlefield, it triggers, returning Fiend Hunter from your graveyard to the battlefield.
When Fiend Hunter enters the battlefield, its first ability triggers, exiling Hero of the Dunes.
Resolve the Altar of Dementia ability from step 1, causing target player to mill cards equal to Fiend Hunter's power.
Repeat.

Infinite death triggers

Infinite creature ETB

Infinite creature LTB

Infinite mill

Infinite creature sacrifice triggers

Infinite self-mill

Hero of the Dunes

Fiend Hunter

Altar of Dementia

Activate Viscera Seer by sacrificing Fiend Hunter.
When Fiend Hunter dies, its second ability triggers, returning Hero of the Dunes to the battlefield from exile.
When Hero of the Dunes enters the battlefield, it triggers, returning Fiend Hunter from your graveyard to the battlefield.
When Fiend Hunter enters the battlefield, its first ability triggers, exiling Hero of the Dunes.
Resolve the Viscera Seer ability from step 1, causing you to scry 1.
Repeat.

Infinite scry 1

Viscera Seer

Activate Ashnod's Altar by sacrificing Fiend Hunter, adding {C}{C}.
When Fiend Hunter dies, its second ability triggers, returning Hero of the Dunes to the battlefield from exile.
When Hero of the Dunes enters the battlefield, it triggers, returning Fiend Hunter from your graveyard to the battlefield.
When Fiend Hunter enters the battlefield, its first ability triggers, exiling Hero of the Dunes.
Repeat.

Infinite colorless mana

Ashnod's Altar

Activate Goblin Bombardment by sacrificing Fiend Hunter.
When Fiend Hunter dies, its second ability triggers, returning Hero of the Dunes to the battlefield from exile.
When Hero of the Dunes enters the battlefield, it triggers, returning Fiend Hunter from your graveyard to the battlefield.
When Fiend Hunter enters the battlefield, its first ability triggers, exiling Hero of the Dunes.
Resolve the Goblin Bombardment ability from step 1, dealing 1 damage to any target.
Repeat.

Infinite damage

Goblin Bombardment

Activate Blasting Station by tapping it and sacrificing Fiend Hunter.
When Fiend Hunter dies, its second ability triggers, returning Hero of the Dunes to the battlefield from exile.
When Hero of the Dunes enters the battlefield, it and Blasting Station trigger.
Resolve the Blasting Station trigger, untapping it.
Resolve the Hero of the Dunes trigger, returning Fiend Hunter from your graveyard to the battlefield.
When Fiend Hunter enters the battlefield, its first ability and Blasting Station trigger.
Resolve the Blasting Station trigger, untapping it.
Resolve the Fiend Hunter trigger, exiling Hero of the Dunes.
Resolve the Blasting Station ability from step 1, dealing 1 damage to any target.
Repeat.

Blasting Station

Activate Phyrexian Altar by sacrificing Fiend Hunter, adding one mana of any color.
When Fiend Hunter dies, its second ability triggers, returning Hero of the Dunes to the battlefield from exile.
When Hero of the Dunes enters the battlefield, it triggers, returning Fiend Hunter from your graveyard to the battlefield.
When Fiend Hunter enters the battlefield, its first ability triggers, exiling Hero of the Dunes.
Repeat.

Infinite colored mana

Phyrexian Altar

Activate Saffi by sacrificing it, targeting Hero of the Dunes
Activate Viscera Seer by sacrificing Hero of the Dunes
When Hero of the Dunes dies, Saffi triggers, returning Hero of the Dunes from your graveyard to the battlefield.
When Hero of the Dunes enters, it triggers, returning Saffi from your graveyard to the battlefield.
Resolve the Viscera Seer ability.
Repeat.

Saffi Eriksdotter

Activate Thermopod's second ability by sacrificing Fiend Hunter, adding {R}.
When Fiend Hunter dies, its second ability triggers, returning Hero of the Dunes to the battlefield from exile.
When Hero of the Dunes enters the battlefield, it triggers, returning Fiend Hunter from your graveyard to the battlefield.
When Fiend Hunter enters the battlefield, its first ability triggers, exiling Hero of the Dunes.
Repeat.

Infinite red mana

Thermopod

Cast Glider Staff by paying {2}{W}.
When Glider Staff enters, it triggers, airbending Hero of the Dunes
Activate Krark-Clan Ironworks by sacrificing Glider Staff, adding {C}{C}.
Cast Hero of the Dunes from exile by paying {2}.
When Hero of the Dunes enters, it triggers, returning Glider Staff from your graveyard to the battlefield.
Repeat from step 2.

Combos with "Hero of the Dunes"