Man, this episode was GREAT!
This is way better than Faiz having an identity crisis, as someone else theorized before the episode came out. And I love the way they are handling it! A stunt double that looks like Gentaro from behind, clips and photos from the show (unless that Zodiarts battle was recreated), using voice clips from the original actor (or a really good sound-alike, I couldn't tell), and then having his lack of appearance be justified behind a good plot while letting other returning Riders have center focus?! This is how you do it! With this one episode, Zi-O just became WAY superior compared to Decade.
And can I just say how awesome it is that we saw timeline altering in real-time? Now we finally understand how it works. Once the watches/Another Riders come into play, history is altered. The Riders cease to exist as we remember them, and so do their monsters and every threat they ever faced, leaving only Another Rider. And even when Zi-O takes the Ride Watches, history is still altered. A confusing start for how this time altering stuff works, but it's finally beginning to make sense.
And I even enjoyed the .5 special with that bit of trivia about Shotaro Ishinomori and how it relates to Sougo's name. I love behind the scenes trivia like that. Now if only we could get an explanation for why Sougo wants to be a king. That's still gone completely unexplained, and it bothers the heck out of me, but not enough to ruin this experience.