Kingdom Hearts vs Kirby

Connection:

Both are edgy video game antiheroes that walked the line between good and evil, even starting out as a villain before joining the good side

Both are rivals to the main protagonists who are the chosen ones (Sora for Riku and Kirby for Meta Knight), occasionally fighting at times

Both are proficient and skilled with their swords (Braveheart and Galaxia respectively)

Both a part of a light organization (Seven Guardians of Light for Riku and Star Warriors for Meta Knight) who combat evil masterminds of darkness (Master Xehanort and Nightmare respectively)

Both also have evil dopplegangers (Riku Replica and Dark Meta Knight respectively)