Captain Storm, Cosmium Raider + Lesser Masticore + Maskwood Nexus + Phantom Train

Captain Storm, Cosmium Raider

Lesser Masticore

Maskwood Nexus

Phantom Train

How it works

1. Activate Phantom Train by sacrificing Lesser Masticore.
2. When Lesser Masticore dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When Lesser Masticore enters the battlefield, Captain Storm triggers, putting a +1/+1 counter on Lesser Masticore.
4. Resolve the Phantom Train ability.
5. Repeat.

This ingenious loop turns Lesser Masticore into an immortal engine by abusing the interaction between state-based actions and creature types. With Maskwood Nexus granting all creatures the Pirate type, Captain Storm, Cosmium Raider is able to target Lesser Masticore with a +1/+1 counter every time it enters the battlefield, which immediately neutralizes the -1/+1 counter left behind by its persist ability. Meanwhile, Phantom Train acts as the sacrifice outlet that kicks off the cycle, letting you bin the Masticore over and over to continuously grow your board with infinite enters-the-battlefield, death, and sacrifice triggers.