Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Blasting Station + Vengeful Vampire

Decks

How it works

—

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.

In which brackets is this combo allowed, per Spellbook's Spicy tier?

1–2 · Exhibition & Core

Spellbook classifies this as Spicy — not for these brackets.

3 · Upgraded

Allowed in this bracket.

4–5 · Optimized & cEDH

All combos are allowed.