Blasting Station + Thran Vigil + Gravelgill Axeshark

Blasting Station

Thran Vigil

Gravelgill Axeshark

How it works

1. Activate Blasting Station by tapping it and 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. Thran Vigil and Blasting Station trigger.
4. Resolve the Thran Vigil trigger, putting a +1/+1 counter on Gravelgill Axeshark.
5. Resolve the Blasting Station trigger, untapping it.
6. Resolve the Blasting Station ability from step 1.
7. Repeat.