You're not locked in, either. You can end the loop with infinite flying 6/6s with haste by just opting not to put any more lore counters on your Esper Terra clones (it says up to three). Tifa Lockhart ...

Recluse Magic Cocktail combos; Three affinity of the same type; Magic: Magic surrounds the enemy, continually dealing damage: Fire: Casts a fire AOE attack that continues to burn the area ...

Over in Standard, Sorceress's Schemes forms part of a clunky but amusing infinite combo. Credit for spotting it goes to Redditor Hexanhort, who noted the combo in a discussion in the r/MagicArena ...