These people all of a suddenly hopping on the ban wagon to prove Scott as a third Nogitsune.... HAHAHAHAHAHAH No.
Yes he went under, he too left a door ajar in his mind. Yes, but... Scott is the main character of Teen Wolf aka he has what I like to call 'main character immunity status'.
IT WOULD BE SUPER FUCKING COOL IF Jeff played up on Scott being the third and maybeeee doing a bold ass move like Scott pulling the ultimate sacrifice, pulling the Nogitsune fully into himself and taking the hit.... and dying. THAT IS FUCKING BALLSY as FUCK!
But let me tell you a thing- Jeff won't do it. Jeff has established that Scott is on his pedestal and can't take damage. He's the hero of heroes, he can do no harm. Scott has to save the day at the end of the day.
It's only Stiles and Allison. They have not been marked/checked. They are strangely missing at parts. Stiles is the obvious Nogitsune while Allison is in the shadows (setting up that arrow trap that looked like the one from beginning of 3A while they were chasing down Boyd and Cora. She's the only one who knew of Isaac at the Hospital, the only one to have known about Katashi (Thus the one who killed Katashi and planted the money, thus framing her father and Derek- Allison was protecting her father))
Scott can't be EVERYTHING- Scott can ONLY be the hero, because that has been his path since DAY FUCKING ONE. Scott's path is to be the best of Alpha's and the best of Heroes.