Blightbeetle + Bartolomé del Presidio + Harmless Offering

Blightbeetle

Bartolomé del Presidio

Harmless Offering

How it works

1. Donate Blightbeetle to an opponent
2. Activate Bartolomé del Presidio 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 Bartolomé del Presidio ability.
5. Repeat from step 2.

This delightfully wicked loop relies on a clever piece of preventive alchemy: by using Harmless Offering to gift Blightbeetle to your opponent, you completely turn off their ability to receive +1/+1 counters. With that static protection in place, your sacrificed undying creature refuses to gain a counter when it returns from the graveyard, allowing it to enter the battlefield fresh every single time. Meanwhile, Bartolomé del Presidio happily feasts on the repeating loop, growing ever larger with each sacrifice while generating an endless storm of death, ETB, and LTB triggers.