Ayara, Widow of the Realm // Ayara, Furnace Queen | Scourge of the Throne | Altar of Dementia

Cards

Scourge of the Throne in your graveyard.
Ayara and
Altar of Dementia on the battlefield (
Ayara on the battlefield as
Ayara, Furnace Queen).
An opponent's life total is higher than or equal to your life total.

At the beginning of your combat phase,
Ayara triggers, returning
Scourge of the Throne from your graveyard to the battlefield, and giving it haste until end of turn.
Declare
Scourge of the Throne as an attacker, attacking an opponent whose life total is higher than or equal to yours.
Scourge of the Throne's dethrone ability and second abilities trigger.
Resolve the second
Scourge of the Throne trigger, causing you to untap all attacking creatures and to get an additional combat phase after this one.
Holding priority, activate
Altar of Dementia by sacrificing
Scourge of the Throne, causing target player to mill cards equal to
Scourge of the Throne's power.
Resolve the second
Scourge of the Throne trigger from step 3, doing nothing.
Repeat each combat phase.