Blightbeetle + Blasting Station + Coveted Falcon

Blightbeetle

Blasting Station

Coveted Falcon

How it works

1. Activate Coveted Falcon by paying 1, turning it face up.
2. Coveted Falcon triggers, causing an opponent to gain control of Blightbeetle and causing you to draw a card.
3. Activate Blasting Station by tapping it and sacrificing the undying creature.
4. When the undying creature dies, its undying ability triggers, returning itself from your graveyard to the battlefield without a +1/+1 counter on it due to Blightbeetle.
5. When the undying creature enters, Blasting Station triggers, untapping it.
6. Resolve the Blasting Station ability from step 3.
7. Repeat from step 3.

This intricate loop uses Coveted Falcon's disguise ability to gift Blightbeetle directly to your opponent, locking down their ability to place +1/+1 counters. With Blightbeetle safely on their side of the battlefield, any creature with undying that you sacrifice to Blasting Station will return to life without the counter that would normally shut off the loop. As the creature repeatedly enters and hits the graveyard, Blasting Station untaps itself to deal infinite damage while fueling endless sacrifice and death triggers.