I am curious are there any (XianXia) novels where MC or close to him follows a Xiumo/devil/evil cultivation path, regardless of his viewpoint if he is good/neutral/evil himself. I have seen them till know as side-characters or mainly enemies of their respective novel. An example should be newly added Yi Chenzi from ISSTH
The guy from Martial God Space use devil skills and his helper was a sentient mirror used by the previous demon king
Xian Ni yeah but not at first, I don't remember how long before he learns it but that's the best example. There could be Martial God Space as well, he learns skills from the devil's race as well as 'normal' skills
I think it was 100 chapters in that it got seriously devil's way, but it was always a bit skewed in that direction.
This novel Zhu Xian has what your looking for takes a bit to get started and tranlaters switch names but it is a good read. http://www.novelupdates.com/series/zhu-xian/ Taken from a summary in the review by Melakias] A terrible calamity has fallen onto Zhang Fan, not only becoming one of the three survivors of Grass Temple Village, where everyone else was horribly massacred, he was also tasked to carry one of the most evil artifacts, the Sinister Bead, and taught one of the most secret teachings of the Skysong Sect, the Brahmin Wisdom. Now he cultivates in the Jadeon Sect, his knowledge and possession will draw him into a chaotic story where he will have to carry some of the greatest burdens of the Martial World.
I don't think so, well I don't think he'll follow a route to be precise, he doesn't need it. He'll just learn from every path because he can easily do so.
The MC is Zhu Xian gets a couple things that slowly push him towards it, though where I've read up to he hasn't actually done anything bad yet.
Zhu Xian !!!!!! The MC begin in the righteous faction but he will make contact with an evil power without realizing it. A master xanxia work !
Try World of Cultivation the Mc is possessed by a demon spirit. He still has his facilities but if he try anything that's against the demon spirit it will probably kill him. While he's hosting the demon it's giving him technique that's probably evil but I'm not too sure since I'm still on chapter 35ish.