Anyone know a manga with half demon uke with dark skin?

Maybe what you're finding is a work of Yamane Ayano, Crimson Spell. The uke is being possessed by a demon whenever he wields this ancient sword.

What’s the name of the manga which the seme is a mountain god and the uke is half demon that eat the dew from the seme’s roots? He has roots stick to his body... I wonder if anyone could help me find this manga about mountain god (black long hair seme with tree root tentacles) who raises and lives with half demon uke (dark skin with little horns)? The uke was living on seme's dew that comes from his tree roots.

-from two other forum posts by the OP

I think they're looking for this specific manga, but I've never read it. Hope condensing this here will be of some help.