Yenna, Redtooth Regent

The engine here has an unusual governor built into the target clause: you can only copy an enchantment that doesn't share a name with another permanent you control. That single restriction quietly turns the ability into a breadth machine rather than a doubling one. You cannot make an army of the same enchantment; you can only widen your board with copies you don't already have, which pushes the deckbuilder toward a diverse toolbox of one-of enchantments rather than a single best target. The Aura rider is where the design opens up. Copy an Aura and Yenna untaps herself and scries 2, so the tap ability stops being once-per-turn: chain enough Auras and the activation becomes a repeatable, card-filtering loop within a single sorcery-speed window. That untap is the pressure valve the whole card is balanced around, since without it the enchantment-copying is a slow value grind, and with it the card becomes an engine that pays for itself while smoothing your draws. The tokens dropping their legendary supertype matters too: it lets her duplicate legendary enchantments (God enchantments, legendary Sagas and Auras) without the legend rule forcing you to put one into the graveyard, so the copy sticks and starts its own chapter counters or triggers from scratch. She sits at the head of a green-white enchantment archetype that had long been more about static payoff cards than active generators, and gives that shell a proactive commander who builds a wide, varied enchantment board one activation at a time.