Stalwart Successor + Blasting Station + Twilight Shepherd

Stalwart Successor

Blasting Station

Twilight Shepherd

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. When Twilight Shepherd enters, Blasting Station and Stalwart Successor trigger.
4. Resolve the Blasting Station trigger, untapping it
5. Resolve the Stalwart Successor trigger, putting a +1/+1 counter on Twilight Shepherd
6. Resolve the Blasting Station ability from step 1
7. Repeat.