While I wasn't surprised when Necrom appeared and had Aran's voice, I couldn't help but roll my eyes a bit, because it was just waaaay too obvious. But seeing how proud and happy his actor was about becoming a Kamen Rider, saying something along the lines "I'm so excited to become one of those heroes I really looked up to", I can't even be mad or disappointed. He's a very likeable guy, so maybe Aran might become a likeable character as well now xD

He got rid of his stupid scarf so that already an improvement in my book xD

Now! I will compare 3 Riders with Sonic Characters!

Takeru is Sonic as both of them are the only one are very heroic and too nice

Makoto is Knuckle as both of them start out as a rival to main character and was anti-hero but eventually start helping out the heroes!

Aran is Shadow as both of them are very anti-hero and considered the most ruthless character!

I'm not sure it was meant to be that much of a mystery. Maybe it seemed that way from our point of view when they didn't show Necrom's civilian form in any scans. I feel like it was really more fan speculation over complicating things than Toei explicitly going "OOOOOH! WHO'S THIS MYSTERY MAN? WHO COULD IT BE?"

No, and good one. I meant his actors name!

https://www.youtube.com/watch?v=_F-2k_23yaA

Hayato Isomura.

Necrom's first appearance in the stage show.

He will first appear in-show at episode 16.

https://www.youtube.com/watch?v=8dzRaWoFGnQ

They made a hella big deal out of it in the movie. And for children, this might also have been an exciting question. Also, if they never wanted it to be a mystery, they could just have Alan hold the Eyecon more often and have him talk more about it... but they didn't. So yes, it was supposed to be a mystery.

No, what I'm getting at is like... NECROM is the mystery and the reveal; not who he is. I mean, think about it. They kept the Houdini Eyecon's sticker hidden for a few episodes. We never questioned that Specter was going to be the one eventually using it, but from a narrative standpoint, the mystery there was "what is this Eyecon?"
Sort of similarly, if you had ONLY watched the show and never payed any attention to promo fliers or magazines, the first glimpse or mention of Necrom is the shot of the Eyecon in the preview for this week's episode. From there, you see those are Alan's fingers and would go "Oh! Alan was planning/creating something in the Ganma world several weeks ago. That's probably what it was!" From a perspective like that, it's more of surprise to the viewer that Alan is becoming a Rider, and less that the Rider is actually Alan.

I'm not sure if what I'm saying is clear, but basically it's all about point of view. I suppose from a marketing and publicity standpoint, the Necrom situation was a little bit like a "whodunnit?" But only from there. I don't think the show itself was ever keeping Alan AS Necrom a secret. It was more keeping Necrom's existence AT ALL a secret. The problem there being Kamen Rider media and advertising doesn't play well with tight reveals like that. You can't just keep something like that hush-hush and expect to sell toys the day they're revealed.

Am I the only one that noticed that Alan's outfits are essentially the same design, just different material and coloring?