Mostly Entertaining but ultimately an indulgent mess

Rating: 6/10 (26 September 2017)

I would rate this a 2 star film but because James McAvoy is good value, the other 4 stars are for his performance.
I have deliberately not read any other reviews, just jumped straight to leaving this one having finished watching a scant 5 minutes ago.
It seems to me reading the trivia section, that M. Night Shyamalan just loves himself, from appearing in his own films (no, I did not know that) and referencing his previous films that many viewers (myself included) may not have seen, and rendering the final scenes of "Split" into the kind of gibberish spouted all along by James McAvoy's character(s).
The 'heroine in peril' moment towards the end was dragged out for so long I was muttering "Come on, give us a twist or just end it". I got my wish - within 5 minutes it was ended with an apparent twist I just didn't get at all (that's right! Because I was supposed to know all about some previous film which I had never seen). Total crock of crap, I'm sorry.
Dr. Fletcher ought to have been locked up herself, allowing a bunch of personalities to take control of poor Kevin, who had not seen the light of day himself since 2014. Just like many in the medical profession, for the sake of a good published paper she had no problem with Kevin being incarcerated somewhere inside himself while the criminals he harboured ran amok in all directions. Obviously interviewing them was more important than Kevin's wellbeing and public safety.
At the beginning, when the three girls were abducted, Casey was so passive and weird I was expecting to discover she was a party to the abduction. Well apparently she wasn't. She was just traumatised by past events in her own life that ultimately had no real bearing on her character's behaviour, unless we are supposed to applaud that she eventually fights back (if you can call shutting yourself in a cage and being willing to fire at a crazy man as liberating in some way). I mean, who wouldn't fire at him in the same circumstances, whether you had a sense of deja vu or not?
The final 5 minutes were total nonsense for anyone who has not seen whatever film it was we were all supposed to have a light bulb moment over. At best it is cavalier behaviour towards the viewer, who will likely be confused when the whole film collapses into an incoherent mess, and at worst it shows what hubris can do to a man, that he would hang the ending of a film on a previous work because he is too important and full of himself to bother finishing it in a way everyone can understand.
(Spoiler alert: Bruce Willis? What? A man in a wheelchair 15 years ago? What? Mr. Who?). That may not have been a spoiler for you ... if so, welcome to the club!
Crap, crap, absolute crap. And if anyone is moved to think "Stupid Reviewer, fancy not knowing blah blah blah ..." it is really unattractive to lord it over other people because they don't know squat about this director's previous films. Why should we? That's just buying into his little superiority club and being self-congratulatory. Perhaps I should binge view every film that has ever been made by living directors in case another one decides to follow suit!
I have never seen such a mess and deflating ending in ages and I'm sorry about that. M. Night Shyamalan, shame on you. You don't deserve the veneer of respectability and professionalism conferred on this film by Mr. McAvoy. I sat and watched it for 2 hours and you ridicule me by offering an ending for the "in crowd". So maybe now I know how Casey felt all this time, on the outside with the other girls laughing at her. Eat as many burgers as you like in your next film - I won't be admiring your cameo because I won't be watching.