Woe Strider + Gravelgill Axeshark + Hardened Academic

Woe Strider

Gravelgill Axeshark

Hardened Academic

How it works

1. Activate Woe Strider by sacrificing Gravelgill Axeshark.
2. When Gravelgill Axeshark 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 Gravelgill Axeshark.
4. Resolve the Woe Strider ability.
5. Repeat.