User blog comment:BannedLagiacrus/Monster Appreciation Week: Vaal Hazak/@comment-4969421-20180823182041/@comment-5020152-20180823221625

Another tiny yet fantastic detail - I've noticed from gameplay videos that Vaal's skin is normally a cloudy white color, but sometimes clears up to become this beautiful shade of iridescent silver. It's exactly like how the minion monsters in the Vale have those dark blotches on their bodies from the effluvium, which makes sense because Vaal is carrying the effluvium with him all the time.

You're absolutely right, Vaal looks pretty cool on the surface but becomes straight-up phenomenal when you take the time to look into the details.