I suppose it doesn't make much sense to put in a dead link as the source, but I figured I'd include it if helps finding the artist.

Well, according to saucenao, this was drawn by 966. I'm not sure that's enough evidence to tag it though.

Thömas said:

Well, according to saucenao, this was drawn by 966. I'm not sure that's enough evidence to tag it though.

Looking at their coloring technique and considering their Pixiv account is dead, I would say that's a safe guess at least.