After some prompting by a developer over at ValvE, I've reformatted my Dota2 Ancients illustration for use as a 16:9 loading screen, and submitted it for consideration in Steam's "Workshop" marketplace. You can see the submission here: steamcommunity.com/sharedfiles… Upvote it if you want to see it in the shop!
I'm afraid I must decline if it's being sold. I don't mind free redistribution, but I myself am not selling this outside of Steam Workshop because I am uncomfortable with monetizing fanart of someone else's IP outside of official channels. So you can go ahead if the theme is being given away free, but not if you're selling it.
Holy, amazingly incredible! These Ancients are stunning and The Designs look radical! The plant life, boulders, textures, effects, sky, fire, water, sky, clouds, atmosphere, concept, composition, uniqueness, style, colors, lighting, and other details are also spectacular! Awesomely epic work!