Warning SPOILERS : The film was a bit underwhelming if compared to other films in the Superhero genre. But as a standalone storyline based on the two previous films in this trilogy, I would say it's up to par.
However, M. Night Shyamalan's final twist seemed forced and too reminiscent of other well known conspiracy theories. The 10,000 (!!!) year history of a secret society who obviously missed covering up the existence of other superpowerful human heroes and villains such as Samson, El Cid, Joan of Arc, Genghis Khan, Einstein, Sir Isaac Newton, Hitler, Josef Mengele, etc was poorly thought out. The best conspiracy theories are the ones rooted in truth which causes the audience to ponder its veracity in real life. If he had shortened the history of the secret society to having existed for the last 60 years, it would have been much more plausible.
And if it wasn't for the excellent acting abilities of the stars, and the way the heroic journey unfolded prior to the secret society plot twist, I would have given this film a lower rating. 3 out of 5 thumbs up.