>>47357204Most would be defeated, but things will change depending upon the tactics the Pokemon take. Malamar for example would be great for infiltration and sabotage. Imagine a situation where it's enthralling the minds over a nation with nuclear weapons. Rotom/Porygon would also be incredibly useful for taking advantage of the military's reliance on technology & infrastructure respectively.
If it's just some medieval dumb style fight then most die, so I'm assuming it's a modern take on warfare. Some Pokemon would serve as shock troopers doing casual city level damage while the more versatile mons like example above will do the real work.
The weather trio by itself is going to make our climate change issues worse, while some nasty poison types start a new pandemic.
No need for Arceus or the creation trio to get involved, really. If anything it could pose as the deity of some religions and further sow dissent. Warfare is very psychological, so why not have some fun? Also, image related has resurrection powers for all deceased shock troopers and possibly itself. Hell, whose to say resurrected humans will not be converted into Pokemon soldiers?