Forum Necroscribe + Priest of Forgotten Gods + Traitorous Greed + Bridge from Below + Living Lightning

How it works

Cast Traitorous Greed by paying .
Forum Necroscribe triggers, returning Living Lightning from your graveyard to the battlefield.
Resolve Traitorous Greed, untapping Priest of the Forgotten Gods, giving it haste until end of turn, and adding .
Activate Priest of the Forgotten Gods by tapping it, sacrificing Living Lightning and any creature not part of the combo.
When Living Lightning dies, it and Bridge from Below triggers.
Resolve the Living Lightning trigger, returning Traitorous Greed from your graveyard to your hand.
Resolve the Bridge from Below trigger, creating a creature token.
Resolve the Priest of the Forgotten Gods ability, causing any number of opponents to sacrifice a creature and lose 2 life, adding , and drawing a card.
Repeat, sacrificing the newly created token in step 4 instead of the additional creature.

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

1–2 · Exhibition & Core

Allowed in this bracket.

3 · Upgraded

Allowed in this bracket.

4–5 · Optimized & cEDH

All combos are allowed.