Glad to see other people in Houseki no Cosplay Hell.
If you want to go with a wig and not something that is built up, I've seen a few ways to appraoch this. Most cosplayers just go with a regular wig, but you want extra shine. I've seen people add highlights to their wigs, whether with glitter or something shimmery or just airbrushed on where highlights would go. I've seen a few examples, can't find any at the moment of someone airbrushing highlights to mimic the anime-style shine, but this Amethyst
is a good example of what I mean with using shimmer as a highlight. Another option would be doing gradient effects to mimic a shiny look without any actual shine -- this is a Diamond wig
, but it illustrates the principle.
As for styling, I would do chunky, pieced spiking, but directed downward rather than up or out like spikes would be. You can achieve this by sectioning out the hair and using hairspray and a hairdryer to set it. (I'd use a freezing spray)
Though, if you want a screen-accurate look, you'll have to build it out of something other than wig. One crossed my Twitter timeline the other day that was made out of a shiny vinyl or cellophane or similar and it looked pretty good, so I know it's been done.