My proposal is rather short and straightforward: disallow Aurora’s Creation on Legendary creatures.
Legendary Creatures are legendary for a reason, and very often Aurora’s Creation on them makes a really huge swing, like having extra Garudans or Auroras can be rather devastating.
Also, flavor-wise, having more than one Legendary on board is strange. I always cringe on Aurora’s Creation for Aurora herself (chicken, err, turtle and an egg problem there).
MTG strictly disallows multiple uniques at all, Scrolls disallowed it only on one side of a board, I think it makes sense for Faeria to follow this path too.
The problem I have isn’t so much with the legendaries in general, it’s just Magda and Garudan which are just horrific cards to deal with anyway. There are a few others that are obnoxious to see twice but none of them seem anywhere near as unfair.
If the two of them were to be changed it would be less disgusting I think.
Magda and Garudan have their own problems. Design-wise, I think, disabling cloning the Legendaries would enable developers to create better legendaries in the future, as they wouldn’t be constrained by the fact you could have 4 of them on the field with an Aurora’s Creation.
Speaking of which, I think there is the same issue with an Egg of Wonders, but then without more high-cost regular creatures Egg of Wonders would become too weak.
Egg of wonders is less of an issue because a lot of the time the real power from a wonders is on it’s gift or last words. Even the dragons are only 6/6 flying charge 2. If you compare that to the things like icebound behemoth that body isn’t terrifying.
Could potentially just have egg of wonders and aurora’s creation give a blank text-box version. So outside of flying/aquatic/charge it has no text.