Mikaeus, the Unhallowed + Altar of Dementia + Furystoke Giant

Mikaeus, the Unhallowed

Altar of Dementia

Furystoke Giant

How it works

1. Activate Altar of Dementia 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 Altar of Dementia ability.
4. Activate Altar of Dementia 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 Altar of Dementia ability.
7. Repeat.