Mordenkainen + Doubling Season + Thassa's Oracle

Powerful

Decks

How it works

Your devotion to blue is equal to or greater than the number of cards in hand minus two.

Cast Mordenkainen by paying .
Mordenkainen enters the battlefield with ten loyalty counters due to Doubling Season.
Activate Mordenkainen's third loyalty ability by removing ten loyalty counters from it.
Mordenkainen dies as a state-based action due to having zero loyalty.
Resolve the Mordenkainen ability, exchanging your hand and library.
Cast Thassa's Oracle by paying .
Thassa's Oracle enters the battlefield, causing you to win the game.

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

1–2 · Exhibition & Core

Spellbook classifies this as Powerful — not for these brackets.

3 · Upgraded

Allowed in this bracket.

4–5 · Optimized & cEDH

All combos are allowed.