i recall the "demon spirit devouring technique" not sure if it was only novel: it was possible to use the demonspirits (they use to fuse and fight) and to take the energy(soul) of them and turn them into cultivation but had a limit how much u can get before it gets damaging for the cultivation
PS: might be the part where he is in the heavenly sacred boarder chapter 114.5 (when he aborbs the spirits to expand his soulrealm)
Yes, but "he's" a "Mulan". The leadership of the sects are supposed to have male heirs, but since the only disciple the Netherrealm Master has is female, she's being raised as a man until she can take over the sect.