China is getting wings

[Thunda_Cat_SMASH]

Small correction here: Ysayle DID use crystals to turn into Shiva in her attempt to fight Ravana. The area she did so had a good bit of crystals surrounding it (I believe they actually focus on a cluster of them to show that off as she is transforming). I can check the cutscenes if you want to make sure but it is what I remember. But the amount of crystals she had at her disposal was less than how much Ravana has when he was summoned (before even getting into us at the heart of his land near all of his worshippers) so it didn't work.

And yeah, trying to compare Primal Summoning to a weapon/weapon style is Apples to Watermelons.

Going purely off of memory, Ysayle did it by giving herself up to Shiva, rather than by using crystals. There are crystals that sprout from where Ysayle stands, but they're more ice crystals, iirc, rather than ones filled with aether. Incidentally, PCs can already do something like that as a SMN through Dreadwyrm Trance.