The moment I saw the cover art for the fic, I instantly recognised it as yours. I reckon it's neat that you have such a unique style, as it leaves a rather hard to forget impression. I found this image to be great on the eyes too. Fun to look at and stuff.
Please do us all a favor and start submitting your work to any place that uses artists. Your style is marketable and visually pleasing. Your pony art is beautiful and dark and romantic. I'm fairly certain you can shift that style into just about any subject you wish.