Some grammatical nitpicks:
The wording "that" is ambiguous; I know you probably mean that there is no war, famine, discrimination and religion happening in Oak's time, but it could also be easily misinterpreted that all those things weren't happening in the earlier time period Oak is reading about.
When I was a young child, I had read about war, famine, discrimination and religion and with none of that happening in that time
, I truly thought of it as a modern and metropolitan age.
For clarity's sake as well, place a comma between "and" and "with."
Change the comma in red to a semicolon or a period.
... and the money dangled before me like a carrot in front of a donkey was all the persuasion I needed,
I accepted and immediately started into creating sentient Pokémon.
First comma in red could be a period or a semicolon. The second should be a period.
Research was none-too-strenuous,
quickly, I had found that crossing human and Pokémon Deoxyribonucleic Acid could create a race of anthropomorphised Pokémon (when discovered, the media dubbed them ‘Pokémorphs’ I still prefer anthropomorphised Pokémon),
they kept the main features of their body, but they had become bipedal and more human shape.
Comma in red should be a period.
For twenty years, Pokémorphs and humans got along,
those who had changed still went around training feral Pokémon and battling against the Elite 4 of each region and those who had decided to stay human still did as they always did.
I don't get the second sentence. Feels repetitive. Feels kind of clunky as well with the "there would not actually be."
I thought of it as petty and that each side would calm down after the election. Although, there would not actually be an ‘election,’ we still have not got one now.
hung above Mount Moon eerily, casting a moonlit shadow
over the group of tents.
moonmoonmoonmoon *shot* Moon shouldn't be capitalized (for the record, you only capitalize words like "moon" or "sun" if its in context with other celestial bodies, like Earth).
Shadows cannot cast "moonlit" radiance; they are cast because something is blocking the "moonlight." I get what you mean, though. ;P Personally, I'd get rid of it because you already have two "moons" in this sentence.
People still use "skew-whiff" these days?
The tents, each set up perfectly, none of them were
lopsided nor skew-whiff, and the khaki colour blended in –sort of- with the background. The tents had been arranged in a circle, in the centre,
a pole rose up fifty foot at least and at the end of it waved a flag. The flag was white, symbolising neutrality and surrender. Each tent had a square hole cut out of the top, smoke belched
out of a few of the holes.
Most of the sentences need to be retweaked because they are incomplete or there's a comma splice somewhere. Example edit:
The tents, each set up perfectly, were not lopsided nor skew-whiff, and the khaki colour blended in –- sort of -- with the background. The tents had been arranged in a circle; in the centre, a pole rose up fifty foot at least, and at the end of it waved a flag. The flag was white, symbolising neutrality and surrender. Each tent had a square hole cut out of the top, smoke belching out of a few of the holes.
Comma in red should be a period. Put a hyphen between the "pokemorph/human-controlled" words.
Those who lived there called it the ‘separation point,
’ on one side was the Pokémorph controlled Cerulean and on the other was the Human controlled Pewter.
Commas in red should be periods.
The darkness inside his
tent made it impossible to see any features. It
stood up and pulled out a square box from its
began to speak into the square box,
the voice was male.
You already indicated that the human was male in the first sentence. So either change the "it"s to "his/he" or change the first "his" to "its."
Anyway! Hello! I like your narrative style. Your first person-narrative was enjoyable (a kind of weird thing to say considering what's taking place). It was an interesting way to tell of the pokemorph's history and the consequences of their creation. You can feel older Oak's regret near the end and his struggle to find peace within the war-torn region.
The scene that took place in Mt. Moon was intriguing though kind of abrupt (the first section of the first person narrative sort of ended on an unfinished note IMO ... not that there's anything wrong with that). Either way, I predict something terrible happening. I wonder why someone want want to set up a neutral camp in between two rivaling sections; it seems that it would be safer to make a camp that is at least some ways away from the fighting. Well, at not in the middle of it. I figure one of the sides is going to try to take over and claim it.
I do mimic everyone else's queries about the pokemorphs not just using their powers to wipe out the humans. Not unless it's more of an aesthetic thing; the pokemorphs just look like pokemorphs but didn't inherit their powers. Still, I figure there might be some physical advantage by crossing the two species. The human side, at least in Kanto, is heavily unmatched (85% pokemorphs o_O), so I figure the fight wouldn't take too long for the pokemorphs anyway.
I also get that someone may not be able to foresee the consequences of creating pokemorphs, but doing it, literally, "for the lulz" is just ... huh at best. I figure there must be a physical advantage in doing it (I assume that the humans who rushed to do it were doing it for some sort of physical, perhaps even mental, advantage) ... And if that's the case, then I'm not sure why the pokemorphs haven't decimated the remaining humans anyway. And if they don't get the powers and just an aesthetic difference (and a new start on life, in a way), I don't get why a human would want to do it. I mean, it's intriguing ... but I feel like the reasoning, perhaps what constitutes the pokemorph, could be hammered out a bit, if not now but in later chapters.
Overall, it's a little shaky in grammar (though not enough to hinder my enjoyment) and you have a good handle on writing first person.