An MC that isn't from earth nor one that reincarnated into a younger body. Just make it about an MC in his OWN world, although this might be harder.
Webnovel mc?
CroniesBoss The former has a large fan base, but you have to be careful to be truly original... while the ladder will be easier to write in a way to get people to enjoy it.... however, I suggest writing for yourself... what do you want to read.;,;.
I'll offer my novel Godking Ascending the Heavens as a case study. It's Eastern Fantasy and first published Oct 1. I am now ranked 22nd in originals as I type this. I think it all depends on what you can write, readers don't mind as long as the story is good.
Lord_of_Potatoes Good advice I’ll be sure to check out your novel!
DeJeL Mm I haven’t seen much successful earth transmigrations yet. Except for a few with systems and whatnot. You do have a point tho because at the end of the day majority mc have that fake righteous persona.
CroniesBoss To answer your question, I think both are challenging in their own ways to write. Although transmigrator is initially easy, since you can write by self-inserting your own reactions to a cultivation world, you need to describe the struggles your character has in learning and growing strong.
For OP dude reincarnating, its easy in that you can pretty much make him rely on his past knowledge to become OP right away/nothing ever really challenges him because of his knowledge, but you need to make a detailed and very interesting backstory.
I took the middle road and just made my MC a dude born in the cultivation world.
Lord_of_Potatoes Also, a successful transmigrator eastern fantasy novel would be Gate of Good Fortune. It's pretty good.
Lord_of_Potatoes 
I’ll check em out.
Must Read!
Azeal Neralum
Synopsis - A single-father saves his child from prison escapees. But, in the process, he dies. As his soul traveled to the realm beyond, a catastrophe of cosmic proportions crushes his soul. Leaving only particles of a complete one.
Saved by a goddess, he becomes a different race with a different name. Now they call him Azeal ...
CroniesBoss
I don't think it matters as long as the story is good/interesting enough. I myself prefer not reincarnation/transmigration novels, but I used to love them. I think readers tend to really like those types at first but get bored of them with time. However, an interesting story trumps all cliches whether they're used or not.