Luminous Broodmoth + Nardole, Resourceful Cyborg + Phantom Train

Luminous Broodmoth

Nardole, Resourceful Cyborg

Phantom Train

How it works

1. Activate Phantom Train by sacrificing Nardole.
2. When Nardole dies, its undying ability triggers if it didn't have a +1/+1 counter, and Luminous Broodmoth triggers if Nardole didn't have flying.
3. Resolve the undying trigger, if applicable, returning Nardole from your graveyard to the battlefield with either a +1/+1 counter on it.
4. Resolve the Luminous Broodmoth trigger, if applicable, returning Nardole from your graveyard to the battlefield with a flying counter on it if the creature is still in your graveyard.
5. Resolve the Phantom Train ability.
6. Repeat.

This clever loop centers around Phantom Train, which lets you sacrifice Nardole, Resourceful Cyborg to fuel its ability and grow with +1/+1 counters. When Nardole hits the graveyard, Luminous Broodmoth steps in by granting its resurrection trigger to any creature you control that lacks flying. Because Nardole's own undying ability also triggers upon death, you can alternate how Nardole returns—sometimes with a +1/+1 counter and sometimes with a flying counter—allowing the moth to continuously catch Nardole whenever the undying clause fails to apply.