Or so the name, Shimmering Skies, suggests
It has an errata confirming the correction, so any character can be chosen, not just the opponents
(6/6/2025) To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a flashback cost), add any cost increases (such as kicker costs), then apply any cost reductions (such as that of The Fire Crystal's first ability)
This includes both erratas and full bannings, and knowing which cards are affected by either will avoid any embarrassing situations at your next event
She doesn't fit in with the rest of the family, as nothing else can quest after her, but she's an excellent way to claw things back in a pinch
The non-enchantment clause is odd but is probably intended to stop coeurl being an easy answer to the sets new Saga Summon creatures