Intruder Alarm + Harmonized Trio // Brainstorm + Pia Nalaar, Consul of Revival

How it works

You control a creature that can tap to produce at least .
You control two untapped creatures excluding the mana-producing creature and Harmonized Trio.

Activate a creature by tapping it, adding at least .
Activate Harmonized Trio by tapping it and two other creatures you control, causing it to become prepared.
Cast a copy of Brainstorm by paying .
Pia Nalaar triggers, creating a creature token.
When the creature token enters, Intruder Alarm triggers, untapping all creatures.
Resolve Brainstorm, causing you to draw three cards and put two cards from your hand onto the top of your library.
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.