Created specialty shaders together with Rick Gilliland near the end of the project
Night Elf Cloaking
The final effect ended up being a more subtle version of this which did not animate.
Our objective was to create a more convincing look with minimal added textures, so the effect is really just parallax and some Fresnel.
The second two are just comparisons for with and without the effect, which was later masked to only affect the crystal
For more info please visit the Warcraft III: Reforged Official Website