The twitter account on the source has posted some of kamukamu's art, and then starting posting art like this one that I couldn't find on kamukamu's pixiv. They also linked to a nijie and odabaiko. Their profile picture looks very familiar to me as well, but I wasn't able to find matches to this image on saucenao or iqdb, so I have no idea on the artist.
Isn't it matsuriuta's artwork? I think the earlier ones in this twitter account were drawn to imitate kamu's style. Hell they even literally said "kamukamusensei #".
Yeah, maturiuta sorato goes under the name "Matsu Ryuuta" (松竜太) when he makes lewd art and that's the very name of this Twitter, so I'm pretty convinced it's him rather than kamukamu.