Activate Blasting Station by tapping it and sacrificing Vengeful Vampire
When Vengeful Vampire dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
When Vengeful Vampire enters, Blasting Station triggers, untapping Blasting Station.
Activate Blasting Station by tapping it and sacrificing Vengeful Vampire
When Vengeful Vampire dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
When Vengeful Vampire enters, Blasting Station triggers, untapping Blasting Station.
Resolve the Blasting Station abilities from step 1 and 4.
Repeat.
This loop transforms Blasting Station into a lethal engine by playing on the opposing mechanics of counters. Whenever Vengeful Vampire is sacrificed, its native undying ability brings it back with a +1/+1 counter, which Blasting Station conveniently untaps upon its re-entry to let you repeat the process. Once you swap over to the backside of your commander—Isilu, Carrier of Twilight (the transformed face of Eirdu, Carrier of Dawn)—its static ability grants the Vampire *persist*, meaning the next death returns it with a -1/-1 counter instead. Because +1/+1 and -1/+1 counters annihilate each other upon placement, this clever alternation resets the Vampire's counter state indefinitely, letting you endlessly sacrifice it to deal infinite damage to any target.