Altar of Dementia + Furystoke Giant + Hardened Academic

Altar of Dementia

Furystoke Giant

Hardened Academic

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. Hardened Academic triggers, putting a +1/+1 counter on Furystoke Giant.
4. Resolve the Altar of Dementia ability.
5. Repeat.