Rakdos Joins Up + Zur, Eternal Schemer + Mirror Image

How it works

Activate Zur by paying , causing Rakdos Joins Up to become a creature.
Cast Mirror Image by paying its mana cost. Choose to have it enter the battlefield as a copy of Rakdos Joins Up.
Put Mirror Image into your graveyard due to the legend rule.
Mirror Image's first ability and second ability trigger, along with Rakdos Joins Up's second ability.
Resolve Mirror Image's second trigger and Rakdos Joins Up's trigger, dealing damage to target opponent and causing you to gain that much life.
Resolve Mirror Image's first trigger, returning it from your graveyard to the battlefield with two +1/+1 counters on it as a copy of Rakdos Joins Up.
Repeat from step 3.

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.