What Manga or Doujin is being referenced in this image?

Not sure, but the art style looks a lot like Hirame/Fishine. Where did you find it?

It was on a discounted piece of merchandise belonging to a graffiti artist. They also used a bunch of other anime art for their stuff. Thanks for the artist name though, I'll look it up!

Whoops, meant discontinued.

Yep, you were definitely on point with the artist. The woman on the image is the Witch from Dragon's Crown! Finally at ease with knowing where all those reference came from, thank you very much!