Shilgengar, Sire of Famine + Furystoke Giant + Hardened Academic

Shilgengar, Sire of Famine

Furystoke Giant

Hardened Academic

How it works

1. Activate Shilgengar 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 Shilgengar ability.
5. Repeat.