Jace and Kefnet on the battlefield. Temporal Mastery in hand. available each turn.
Scroll Rack and Kefnet on the battlefield. Temporal Mastery in hand. available each turn.
Muldrotha and Mirror of Fate on the battlefield. Temporal Mastery in hand. available each turn. available to start the loop.
All permanents on the battlefield. Temporal Mastery in hand with mana to cast it every turn. Isochron Scepter with Narset's Reversal imprinted. Mana available to activate Isochron Scepter every turn.