Blightbeetle + Bazaar Trader + Phantom Train

Blightbeetle

Bazaar Trader

Phantom Train

How it works

1. Donate Blightbeetle to an opponent
2. Activate Phantom Train 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 Phantom Train ability.
5. Repeat from step 2.

This clever loop exploits a brutal rules interaction centered around Blightbeetle's passive ability, which prevents your opponents' creatures from ever receiving +1/+1 counters. By using Bazaar Trader to hand that Blightbeetle directly over to your rival, you weaponize its static text against them, ensuring their creatures can never grow. Meanwhile, Phantom Train acts as the engine, letting you continuously sacrifice and pump itself with a relentless stream of loops that effortlessly generate infinite creature sacrifices, enter-the-battlefield, and leave-the-battlefield triggers.