>>39288903here is my never ever pitch idea
In your journey through Galar you find a skyscraper in the metropolitan hub. It is painted with shapes in primary colors. You walk inside and find it's a children's programming network that specializes in making educational games or something for kids. However, a Porygon got into their code and absorbed its whimsy, becoming Porygon-D or whatever. It's Normal/Fairy type maybe and squishy like a ball rather than smooth like Porygon-2. You have to track it down through basic computer based puzzles and then you can capture it or maybe it just joins you. It's cry sounds like silly gurgles synthesized on a computer and it's idle animation is a wobbly bounce.
It is like a regional variant rather than a forme change because it has a new moveset. Instead of Sharpen it gets Bounce or something. Maybe it can have a move called Conversion-D or ebin conbersin :DDDDD that changes all your moves to do neutral damage or something.