As a standalone, Split was understandably open ended mainly because it was setting up for the conclusion to the trilogy. However, I think that it succeeded in the sense that it managed to estsblish a connection between the audience and the Horde and in doing so, got them involved enough in the story to want to know what does happen to the Beast in the third movie. It makes audiences look forward to seeing McAvoy crush his portrayal of 24 different personalities once again and with this, I think M. Night Shyamalan accomplished his goal of generating more interest in the franchise which he started 16 years ago.
All in all, Glass was a perfect antihero despite all of the evil things he has done to accomplish his goals, Shyamalan managed to create a character that had a twisted sense of humanity that audiences can still relate to which is kind of remarkable. The Unbreakable saga takes a while to tell its story, but after 19 years, it did manage to end with a solid conclusion that reconciles audiences with the characters and all that they represent. And that’s a thumbs up in my book.