Ash's adventures are repetitive and losing a bit of its charm.
Well, possibly, but that doesn't mean that a live-action Pokemon film based on the anime should deviate from them. =/ If you were doing fanfiction, then yes, you could, and no one would really care because it's fanfiction. However, if you're talking about a hypothetical live-action Pokemon movie written and directed by someone else, then that's a horse of a completely different color. The reason why is because the Pokemon name, as much as fans would hate to admit it, is often associated with media directed at general audiences. The anime doesn't show a ton of violence and absolutely no gore because children watch it. The games might have twisted hints in the evil teams, but in the end, they're rated E for everyone for a
reason. The Pokemon franchise relies on the ability to market to children as well as the rest of the audience out there, so saying that gore should be added to a hypothetical Pokemon movie for no reason other than you think it's exciting would be losing the target audience that the actual creators are aiming for.
Additionally, Ash's adventures have a certain familiarity to them. While, yes, a company can do rewrites of them in a live-action series (and, in fact, many live-action series based on anime or cartoon shows often do this), the live-action media should still attempt to aim for the target audience of the original
because the name and the source (i.e. the fact that it would be based on the anime) will most likely attract the same target audience. To change the tone of one source of media, most likely, will turn fans of the anime away (because the movie is no longer like the anime).
However, again, it's a different story for fanfiction, but one can assume that you're not talking about fanfiction, considering the fact that this version of the thread is in Pokemon General and not the Writing Lounge. If you want to write a fanfiction about it, sure, go ahead, and good luck. *salute*