As the planned finale of a trilogy of movies, the basic idea for this story has existed in my head, at least in some form, ever since I wrote Myoken the Guiding Light. When I created the Cosmic Gem as a central plot point for that movie, I knew it would eventually turn into something much bigger and lead to a power struggle between Cosmogogue and Nemex. Most of the specifics weren’t there yet, but I had built a framework I would try to follow. I added to that framework when Nemex Unleashed came around. So, as it approached time to write this movie, it all came into filling out that framework I already had.
Celeste was a somewhat later creation for the plot. After writing Nemex Unleashed, I noted how both of the first two movies didn’t really have any strong guest star characters. Meanwhile the actual Pokémon movies tend to be full of them. So, after some consideration, Celeste is who I came up with. Where Nemex Unleashed was purposefully meant to be a story focusing on Ash, Cosmogogue and Celestial Cornerstones was meant to be Celeste’s story.
It could be argued that Celeste stole some of Cosmogogue’s spotlight, which is odd considering that it is the title Pokémon. However, the title Pokémon is typically one of those guest characters, and I wanted to treat Cosmogogue a little differently. After all, Cosmogogue is the Cosmic Architect. Its reveal is something I had been building up to for years. And being a godly entity, it just didn’t seem right to treat Cosmogogue like any old character. Its appearance needed to be big, and needed to be important. Keeping it out until the climax of the movie and having it save the day was the way to do that. But, Celeste, being the Cosmic Champion, served as fill-in for Cosmogogue during its absence early in the movie, which, in a sense, let me have it both ways.
A major feature of the movie was the return of essentially every important character and Pokémon from the first two movies. We had Myoken, Aries, Pleiades, Terratlas, Seluna, Arun, Nemex, and Heliosol all return. This was inspired by my love of the Sinnoh movie trilogy, specifically Arceus and Jewel of Life. I thought it was so cool to have Palkia, Dialga, and Giratina all return from the first two movies, as well as having some cameos of other characters. I wanted to take this to the next level. The return of all the characters really helped to drive in the trilogy aspect of my movies, which was very important to me. Unfortunately, I will admit that the large cast may have been a little too large, leading to some times where we wouldn’t hear from the likes of Aries or Myoken for a little too long. But it really was unavoidable if I was going to have them all as side characters.
Overall, I feel as if I succeeded in the goals I put out when writing this movie, and it is definitely my favorite of the three (though, whether or not it’s better than the Team Rocket Movie is a different story).
To talk about a more specific part, the “World of Pokémon” segment at the beginning was a bit of an oddity. It featured every single Tenno Pokémon and Tennoan Form, including those who have yet to be officially revealed. Being the final Cosmic Quest movie and having just announced that every single Tenno Pokémon has officially had its name revealed, I really wanted to celebrate by including every single one of them in the movie’s opening. And now I can, at the very least, say that every single Tenno Pokémon has appeared in Cosmic Quest, even if it was only properly shown in Cosmic Destiny or even not revealed fully until after Cosmic Quest ends. I do not consider these “cameo” appearance to be the full reveal of a Pokémon, which means they will not have a sprite and Pokédex page added until the time comes where they are properly revealed. It’s odd, but to keep up on my release schedule, I can’t just go and add everything to the backlog all at once. Also, there was a mention of the Tennoan Vanilluxe line, a completely new concept that will remain unrevealed for now. Regardless of the weirdness, I was proud to be able to fit every single Tenno Pokémon into one place after nearly ten years of working on this project.
The Cosmic Quest Official Website 