Like a Boss [Pokemon Fanfic, 2015 PKMNWatties]
15 parts Complete After a Research and Development experiment accident, Giovanni gets de-aged and more doors are opened for him. And yet the first thing he chooses to do is harass Ash Ketchum. Ash is just WTF? Ah well, he'll coerce her to help take over the world with him somehow. Team Flare's a start.
In the meantime, Giovanni learns (sort of) that faking marriages isn't that easy (of course Jessie, James, Meowth muck it up and he ends up married for real), discovers Ash has megalomaniac tendencies in line with his mindset, and traveling across Kalos was going to be one long, epic honeymoon.
On the other hand, Ash happily usurps Team Rocket, makes minions kneel and cater to her whims, and conquers Kalos gyms with OP pokemon and learns that overkill is never a bad thing.
So hello, Kalos! You've got the second coming of Bonnie and Clyde blazing a trail through the region, trolling the law and Flare morons, and causing general chaos in their wake with their pledge to raise hell.
Fem!Ash/Giovanni, harassment of Team Flare, and makeovers abound. Crazy shenanigans included~ Full uncensored chapters available here: http://archiveofourown.org/works/3836353/chapters/8560168