Impostor Syndrome + Combat Celebrant + Tuktuk Rubblefort Combo

All permanents on the battlefield.

An opponent cannot block creatures you control. Combat Celebrant has vigilance.

Declare Combat Celebrant as an attacker, choosing to exert it as it attacks and triggering its ability, causing you to untap all other creatures you control and to get an additional combat phase after this one.

Deal combat damage to an opponent using Combat Celebrant, triggering Impostor Syndrome, creating a token copy of Combat Celebrant that isn't legendary.

During your next combat phase, declare Combat Celebrant and the Combat Celebrant token as attackers, choosing to exert the Combat Celebrant token as it attacks.

The Combat Celebrant token triggers, causing you to untap all other creatures you control and to get an additional combat phase after this one.

Repeat from step 2.

Infinite creature LTB

Infinite creature ETB

Infinite creature sacrifice triggers

Infinite death triggers

Infinite combat phases

Infinite untap of creatures you control

Infinite mana creatures you control can produce

Infinite combat damage