The best buff I could think for
nymph is to enter the play already quinted. But having something entering play almost invincible, that could make other creatures invincible is just stupid.
I concur.
[half-serious rant]
I frankly don't see the point in all of this really. Are you going to use Aether Nymph even if the skill cost is 2? Why not use Anubis instead if it is so much better? So your rainbow deck is Time intensive? So what, you can't have everything your way you know? Use Quintessence instead.
[/half-serious rant]
It's not like it has no use. An upgraded Aether deck based on Spiders and Nymphs is quite handy in terms of dealing fast and somewhat unavoidable damage. Yeah, its use is very limited, so are those of Water and Light Nymphs.