Mikaeus, the Unhallowed + Furystoke Giant + Phantom Train

Mikaeus, the Unhallowed

Furystoke Giant

Phantom Train

How it works

1. Activate Phantom Train by sacrificing Furystoke Giant.
2. When Furystoke Giant dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Resolve the Phantom Train ability.
4. Activate Phantom Train by sacrificing Furystoke Giant.
5. When Furystoke Giant dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6. Resolve the Phantom Train ability.
7. Repeat.