Efreet Flamepainter + Isochron Scepter + Pull from Eternity + Temporal Manipulation

How it works

Efreet Flamepainter does not have summoning sickness and cannot be blocked by an opponent.

Deal combat damage to an opponent using Efreet Flamepainter.
Efreet Flamepainter triggers, causing you to cast Temporal Manipulation from your graveyard without paying its mana cost.
Resolve Temporal Manipulation, causing you to take an extra turn after this one and exile it.
Activate Isochron Scepter by paying and tapping it, casting a copy of Pull from Eternity without paying its mana cost.
Resolve Pull from Eternity, putting Temporal Manipulation from exile into your graveyard.
Repeat each turn.

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

1–2 · Exhibition & Core

Spellbook classifies this as Ruthless — not for these brackets.

3 · Upgraded

Spellbook classifies this as Ruthless — not for these brackets.

4–5 · Optimized & cEDH

All combos are allowed.