Declare Aurelia as an attacker, triggering its ability, causing you to untap all creatures you control and to get an additional combat phase after this one.
Deal combat damage to an opponent using Aurelia, triggering Impostor Syndrome, creating a token copy of Aurelia that isn't legendary.
During your next combat phase, declare Aurelia and the Aurelia token as attackers.
The Aurelia token triggers, causing you to untap all creatures you control and to get an additional combat phase after this one.
Repeat from step 2.

Infinite LTB

Infinite ETB

Infinite sacrifice triggers

Infinite death triggers

Infinite combat phases

Infinite untap of creatures you control

Infinite mana creatures you control can produce

Infinite combat damage

Impostor Syndrome

Aurelia, the Warleader

Deal combat damage to an opponent using the nontoken creature that has haste and the creature that has Breath of Fury attached.
Breath of Fury and Impostor Syndrome trigger.
Resolve the Impostor Syndrome trigger, creating a token copy of the nontoken creature with haste that isn't legendary.
Resolve the Breath of Fury trigger, sacrificing the creature it is attached to and attaching it to the creature token created in step 3, then untapping all creatures you control and causing you to get an additional combat phase after this one.
Repeat each combat phase.

Breath of Fury

Declare Fear of Missing Out as an attacker, triggering its ability, causing you to untap it and to get an additional combat phase after this one.
Deal combat damage to an opponent using Fear of Missing Out, triggering Impostor Syndrome, creating a token copy of Fear of Missing Out that isn't legendary.
When the Fear of Missing Out token enters, it triggers, causing you to rummage
During your next combat phase, declare Fear of Missing Out and the Fear of Missing Out token as attackers.
The Fear of Missing Out token triggers, causing you to untap the nontoken Fear of Missing Out and to get an additional combat phase after this one.
Repeat from step 2.

Infinite self-discard triggers

Near-infinite ETB

Infinite draw triggers

Near-infinite LTB

Infinite rummaging

Near-infinite death triggers

Near-infinite sacrifice triggers

Near-infinite combat damage

Near-infinite combat phases

Fear of Missing Out

Anger

Deal combat damage to an opponent using Myr Battlesphere, triggering Impostor Syndrome, creating a token copy of Myr Battlesphere.
When the Myr Battlesphere token enters, it triggers, creating four 1/1 Myr artifact creature tokens.
Activate Time Sieve by tapping it, sacrificing the four Myr tokens and sacrificing the Myr Battlesphere token, causing you to take an extra turn after this one.
Repeat each turn.

Infinite turns

Time Sieve

Myr Battlesphere

Combos with "Impostor Syndrome"