What makes the build up for Specter's debut in this episode so great is that they started it in the previous episode with his hand. When Specter made his first appearance in this episode, they started with his hand, which tells the audience that the mysterious hand holding a cobra robot in the previous episode is this guy. Once we got our confirmation, we finally got a look at the suit; just multiple shots at the suit, no dialogue, just the suit. It adds up to the mystery of the character, making us wonder if he is an ally or an enemy. The only time we got our confirmation is at the end of the episode, which I will review once we get there.
As for the Ganma's plot in the episode, is basically raising a plot of land and declare it as Nobunaga's castle. The land being shaped of an eye is an obvious choice given the theme of these bad guys. Just like the case with the previous episode, we got the purple glow thing and were averted thanks to Takeru convincing the boss that his life is more precious than his ambition. The only thing worth pointing about this scene is that the raising of the land thing is just recycled footage from the Kamen Rider OOO WONDERFUL movie, which was edited to make it look like it is a new scene. Stay classy Toei.
This is when things start to become interesting for me, since that episode is canon, to some extent, the scene featuring Ghost in the show's 47th episode is also canon. So yeah, when you look at it, Ghost is warning Shinnosuke not to cross over and Takeru became Ghost around the same time Drive is almost done with his fight against the Roidmude. Considering this is the show's fourth episode, Ghost obtained the Newton Ghost Eyecon in between episodes 3 and 4, and in between those times, Shinnosuke is trying to move on with his life without Mr. Belt. That being said, I guess bits of the Kamen Rider Drive movie is non-canon, but since the film involved time travel, I will not dig into it until I watched the movie.
The answer for that question makes sense in the show's context. Turns out for the Ghost Eyecon to appear properly, it needs a righteous soul to summon it. If it is someone with malice says a Ganma who tries to summon it while possessing the guy connected to the item needed to summon the Ghost Eyecon, it might end up differently. Based on that hint and that the next Movie Wars will premiere this December, you can easily conclude that it will not create a heroic Ghost Eyecon, but a Ganma Eyecon. Thankfully, Ghost is there to free Nobunaga's spirit, but before he can turn it into a Ghost Eyecon, Specter arrives.