Look let's be up front, if you're here reading about what Legion could be, we both know what you are looking for.
Legion is awful/awesome. It is quite possibly the least logically sound "A" movie (as opposed to "B" movie) I have ever seen. Which is wonderful, it was exactly what I wanted. We're talking Angelic sepoku, one handed Roc, car wrecks that kill adults but don't bother babies, that guy from Tokyo Drift terrible.
Thankfully, it is not self-aware either. All too often you go into a terrifically abysmal movie and you end up with some middling abomination of meta-this and that. No no, Legion took itself seriously and delivered a must-see for fans of bad movies. If you like it nasty, you're not going to find much worse/better.