>>43237044In interviews, Pokemon staff have mentioned that whatever the habitat within the Poké Balls, it's a comfortable enviroment; Masuda, before the ill will, even joking that it's comparable to a luxury suite. The Gen 4 games also have Lucian mention reading an article about Poké Balls, specifically about why Pokemon are willing to stay inside Poké Balls, stating
> "One article addresses the question why Pokémon would go into a Poké Ball. According to this article, this behavior is based on instinct. A weakened Pokémon will curl up tight in an effort to heal itself. The Poké Ball was invented to take advantage of that protective instinct. "Though, this statement does contradict other statements made, it's made clear that it is comfortable.
The Pokemon Adventure's manga took a lot of liberties with early mechanics and rolled with it, which is why even now certain things in those series don't align with concepts shared by the rest of the series. They even contradict themselves with the mechanics of how the balls even operate within the series, changing over time.
I'm going out on a limb and assuming the other manga was the Gag Manga series, which has shown both clear and regular Poké Balls, but that series purposely avoids making coherent sense.
That Dragonite in the void is Iris's, an already hostile Pokemon, who wears the same expression while walking outside. That specific scene has also been contradicted by other events in the anime as well. The movie, I have not seen, so I can't comment on that; but possibly the Genesect were in custom balls to control them?
There are examples in the games and anime of people befriending and training Pokemon they never actually capture, meaning, that it is possible to tame them, but some Pokemon are mentioned to be too hostile to usually be befriended by other means. There was even a manga where the characters had no concept of what a Poké Ball was, as they only ever traveled with ones they did befriend.