tfw you almost put in Pokemon Origins but then you realize the title would be misleading/confusing

Okay so I'm not sure if we can still post up Pokémon theories here so if not feel free to delete the thread then.

Anyway I wanted to talk about the fan theory about the origins of Pokémon. Now the one I read a while ago has multiple possibilities of how they came about, the closest I can find that was similar is here, go straight to no.11 for it, this also not my theory just to let you all know. This theory talks about how Pokémon could either be the result of a nuclear war, based off Sinnoh myths that Pokémon and humans were once the same species (there were books in DPPt that do mention something similar I believe), or that Pokémon are aliens that invaded the planet and wiped out the animal life and proceeded to imitate the species they have took out.

Now personally I don't believe the first option, while there was war mentioned in the Pokémon games before (Lt. Surge in RGBY, XY) there were also Pokémon around at the time, with IIRC Surge mentioning his own Pokémon that saved him in one; unless there was a war long before any of the mentioned ones I can't buy this one. As for the second and third options, the second sound more toward their version of religious leanings so it's either or, the third sounds more believable since there are indeed alien Pokémon (Deoxys, Cleffa/Clefairy/Clefable, Jirachi, Kyurem to name a few) and possibly my favorite of the three.

I want to know what you all think, do you believe the above three theories? Do you have your own theory as to the origins of these mysterious creatures?