Blasting Station + Kithkin Spellduster + Hardened Academic

Blasting Station

Kithkin Spellduster

Hardened Academic

How it works

1. Activate Blasting Station by tapping it and sacrificing Kithkin Spellduster.
2. When Kithkin Spellduster dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Hardened Academic and Blasting Station trigger.
4. Resolve the Hardened Academic trigger, putting a +1/+1 counter on Kithkin Spellduster.
5. Resolve the Blasting Station trigger, untapping it.
6. Resolve the Blasting Station ability from step 1.
7. Repeat.