Magar of the Magic Strings + Rise of the Eldrazi + Witch-king of Angmar

Decks

How it works

Activate Witch-king of Angmar by discarding Rise of the Eldrazi.
Activate Magar by paying , noting Rise of the Eldrazi and putting it face down on the battlefield as a 3/3 creature.
During your next turn, deal combat damage to an opponent using the 3/3 creature that has Rise of the Eldrazi noted.
The creature triggers, casting a copy of Rise of the Eldrazi without paying its mana cost.
Resolve the Rise of the Eldrazi copy, causing you to take an extra turn after this one.
Repeat from step 3 during 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.