[Switchblade]

Okay, so Faiz's movie is very much an AU story, way more so than probably any other Rider movie. It's not an alternate ending or a slightly different version of the story and it is entirely irreconcilable with the show's continuity. It takes place in a world where Orphenochs have taken over the world and the remains of the human race are barely holding on. I don't consider that a spoiler, as it's the movie's basic premise.

A lot of stuff that happens in the movie does not happen on the show. You will not see Kamen Riders Psyga or Orga on the series, for example. Some things in it will kinda happen but in very different ways. There are two major places where the movie jumps the gun on the series. The first is the debut of Faiz's final form, Blaster form. The other is in the show's biggest plot twist. I'm going to try to be vague, but there's a thing that happens in Faiz that is a VERY. BIG. DEAL. If you want a comparison, think about what it would have been like to watch the Build/Ex-Aid Movie War, about 13 episodes into Build, and to have a scene where Coffee Dad transforms into Evolto, weeks ahead of it happening on the show. It's that level of spoiler.

The best place to watch the movie, if you want to experience the twist in its original context, is after episode 35 (and I feel a little guilty for naming a specific episode here, but it was either that or "wait until character x shows up!").

And if it makes you feel better, this is the only time one of the movies really infringes on the development of the corresponding show's story like this. Most of the others are alternate endings, disconnected AUs, or canonical side stories.