Blightbeetle + Goblin Bombardment + Fateful Handoff

Blightbeetle

Goblin Bombardment

Fateful Handoff

How it works

1. Donate Blightbeetle to an opponent
2. Activate Goblin Bombardment by sacrificing the undying creature.
3. 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.
4. Resolve the Goblin Bombardment ability.
5. Repeat from step 2.

By turning Blightbeetle's continuous prevention of +1/+1 counters against your opponents via Fateful Handoff, you completely break the balancing mechanic of the undying keyword. Once that piece is safely on the opponent's side of the board, sacrificing your undying creature to Goblin Bombardment allows it to trigger and return to the battlefield endlessly. Because Blightbeetle ensures the returning creature never receives its mandated counter, the death-and-rebirth loop can repeat infinitely to burn down any target.