The background lore I had in mind is as follows:
The Crystalwings are a product of the infusion experiments first executed on Adept warrior that had gone missing/or were reported killed during conflicts internally or with other Protoss factions. They were stripped from their glaive cannons and their backwings are heavily modified to generate a local anti-gravitational field allowing for low-altitude flight. The crystalline structure that the Adept warriros were infused with have taken shape much representing a set of wings, allowing Adepts to more naturally redirect and adjust their manoeuvrability. Through the still available psionic abilities the Crystalwing can 'breakaway' tiny shards of the crystalline structure and use arm mounted tethers to 'throw' these shards much like a barrage onto its targets. The latent self-replication properties of the crystal will restore the broken structure in time.
Admittingly, it may not be fleshed out entirely, but this was the general idea for the Crystalwing.
As said, the model is still in WIP and several pieces and effects I still have to do.
[Edit]: @ Davespectre, with reards to the Stalkers running laserlines: no, these are custom created.