Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Blasting Station + Arcbound Fiend

Decks

How it works

—

Activate Blasting Station by tapping it and sacrificing Arcbound Fiend.
When Arcbound Fiend dies, its modular ability and persist ability trigger.
Resolve the modular trigger, putting Arcbound Fiend's +1/+1 counters on another artifact creature.
Resolve the persist trigger, returning Arcbound Fiend from your graveyard to the battlefield. It will not have a -1/-1 counter on it due to its modular ability.
When Arcbound Fiend enters, Blasting Station triggers, untapping Blasting Station.
Resolve the Blasting Station ability from step 1.
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.