You do realize that all youkai can poses people, depending on how strong the person's mental fortitude is right? Ran is second in hierarchy of kitsune-youkai in terms of spiritual capabilities, if Yukari was not careful she could have been taken over or attacked by Ran, because that's how shikigami possesion works. Rason why Chen runs around like a little faggot always without any sort of skill except spooking people is that Ran being as busy as she is because her master sleeps half of the time. thus Ran does not have time to improve Chen's abilities / teach her more about it.
Ran being a kyuubi now is gradually gonna start loosing one of her tails to become a tenko, basically a god kitsune youkai.
Regarding possesion of a body again:
Just how spirits possesed heroines in WBaWC except Youmu who's by default more resilient to them being half-phantom half-human, Reimu and Marisa got brainfucked basically.
The same way a youkai can take over a mind of average human.
Also you are a newfriendo crossie just like anyone who posts this meme, without knowing jack shit about folklore and related.
Next thing you're gonna post is probably the umbrella abuse scene, while again, not knowing that Yukari did it out of conern for Ran's and own wellbeing because it's just how careful she is when dealing with incidents of any sort. If Ran got rekt because she went ahead solve incident without her master, Yukari would be greatly weakened and it could have affected the entire Gensokyo, because no one understands or can fix problems with the barrier like herself, not even Okina. This is why she is so strict with Ran, because she is the only one capable in terms of spiritual power to be near as good as Yukari, Maribel is just a human who can see borders like Yukari but she is nowhere near, and never will be as strong as her unless she also will lose her heart and devout herself to live for over 1k years, still Ran will be more capable than her. The cycle repeasts itself at this point.
Fuck me /jp/ I didn't realize how long this post is until now, I'm just this passionate about this cute, hard working fox.