I had another Pokémon dream last night. It was about a movie on the origins of Pokémon, and it was pretty unsettling for the most part. Not only were Pokémon feared in the past like we see in Legends Arceus, there was a point that they weren't even Pokémon. They were demons. From shadowy figures, gremlins, and ghouls. But before that, there were spirits that people actually got along with. It seems that something changed them...
Fast forward, we got to see a really cool and realistic CG scene of Ho-Oh and Lugia's evolution. The two shared a common ancestor that resembled a cross between Reshiram, Birdramon, and Curse of Dragon. The movie was starting to delve into Mewtwo's story shortly before I woke up. (The whole thing was probably leading up to the debunking of Mew being the ancestor of all Pokémon.)
I also seem to recall ancient "Poké Balls" being talismans and later ones being super hard-core and launched from a railgun.