Blasting Station + Safehold Elite + Hardened Academic

Blasting Station

Safehold Elite

Hardened Academic

How it works

1. Activate Blasting Station by tapping it and sacrificing Safehold Elite.
2. When Safehold Elite 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 Safehold Elite.
5. Resolve the Blasting Station trigger, untapping it.
6. Resolve the Blasting Station ability from step 1.
7. Repeat.