Okay, so this is my idea. It's completely far-fetched and has nothing to do with genetics, because I hope that GAME FREAK will be a bit more creative than that.
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The villainous team is called Team Nova.
Their mission is similar to Team Plasma- to get Pokemon away from people - because, they say, Pokemon suck the life force of the human they are in the service of to power their attacks.
According to Team Nova, Pokemon are completely sentient and are plotting to destroy humanity. The relationship humans have had with them is a total lie. They have been planning to overtake humans ever since the first contact. Every time a Pokemon uses a technique, it siphons away the life force of everyone in the area, but mainly that of its Trainer, whose ownership of the Pokeball strengthens the connection between them.
Of course, this is all a lie.
This makes no sense at all to the scientists of the Pokeworld, and they try to discourage the people from believing Nova's rumors.
However, Team Nova is very skilled at hiding their true motives and making their ideas believable. They even succeed in convincing your character, and you go on a mission influenced by something they say at some point in the game. You, during this mission, discover their true aim: to confiscate all the Pokemon in the world in order to "eliminate" them and create a world without fighting. This is a good idea. If only they weren't trying to send all the Pokemon away. (Not kill them. Send them to the Distortion World or someting) In this world without fighting, Team Nova would be hailed as heroes who stopped the endless conflict which stemmed from the root of Pokemon. Children would be safe, walking from town to town would be without danger, and the world would make more sense in general. And the ruler of it all would be the couple who are the leaders of Team Nova.
One is a man named Adrien who was raised in Kanto, and is the son of Ltn. Surge. After seeing his father fight in the war, he wants to prevent fighting and he believes the best way to do this is to remove the "problem" of Pokemon. The other is Mars, one of the former Commanders of Team Galactic, who got lost when searching for her leader/awkward love interest, Cyrus, and ended up in Kanto, where she met Adrien. From watching Cyrus's speeches, she is skilled at...convincing people of things that aren't true. After some time they got married, and realized that their motives were similar and started a new team together.
Team Nova wants to use the powers of the X and Y pokemon whose names I cant remember to convince the Pokemon that humans are sucking THEIR life force. With X and Y under their control, Nova will be able to communicate with Pokemon telepathically like N does and spread their brainwashing to them.
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And that's MY theory. You better not tl:dr me.