Blasting Station + Twilight Shepherd + Hardened Academic

Blasting Station

Twilight Shepherd

Hardened Academic

How it works

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

This clever loop turns Twilight Shepherd into an immortal ammunition source for Blasting Station, sacrificing the angel to ping any target for damage over and over. The real engine, however, is fueled by Hardened Academic: each time Twilight Shepherd dies, it triggers both its own persist ability (returning it with a -1/-1 counter) and the Academic's static-triggered ability when the card leaves the graveyard. By letting Hardened Academic place a +1/+1 counter on Twilight Shepherd, the counters cleanly cancel each other out, resetting the angel so persist can trigger infinitely while Blasting Station untaps itself on every single entry.