Adarkar Valkyrie + Intruder Alarm + Clever Impersonator Combo

Clever Impersonator in hand.

Adarkar Valkyrie and Intruder Alarm on the battlefield.

Adarkar Valkyrie does not have summoning sickness. You control at least one legendary creature.

available

Activate Adarkar Valkyrie by tapping it, targeting any legendary creature you control.

Cast Clever Impersonator by paying , choosing to have it enter the battlefield as a copy of the legendary creature targeted in step 1.

Put the legendary creature into your graveyard due to the legend rule.

Adarkar Valkyrie and Intruder Alarm trigger.

Resolve the Intruder Alarm trigger, untapping all creatures.

Holding priority, activate Adarkar Valkyrie by tapping it, targeting Clever Impersonator.

Resolve the Adarkar Valkyrie trigger from step 4, returning the legendary creature to the battlefield from your graveyard.

Put Clever Impersonator into your graveyard due to the legend rule.

Adarkar Valkyrie and Intruder Alarm trigger.

Resolve the Intruder Alarm trigger, untapping all creatures.

Holding priority, activate Adarkar Valkyrie by tapping it, targeting the legendary creature.

Resolve the Adarkar Valkyrie trigger from step 9, returning Clever Impersonator to the battlefield from your graveyard as a copy of the legendary creature.

Repeat from step 3.

Infinite death triggers

Infinite creature ETB

Infinite creature LTB

Infinite mana creatures you control can produce

Infinite untap of creatures