So we know how Sylveon evolves from love, and I thought what if the Sylveon we're familiar with is simply one form? What if they looked different based on evolving from different kinds of love for different things?
An Eevee in love with spooky paranormal things like ghosts evolves with pale purples and slightly translucent.
An Eevee in love with space evolves black and purple and with stars on their ribbons and the galaxy in their eyes.
An Eevee in love with nature evolves browns and greens with leaves on their ribbons.
An Eevee in love with art evolves with colorful designs.
An Eevee in love with music evolves with music notes and staffs on their ribbons.
Perhaps they'd have secondary types based on it too?
It's probably a bit redundant and why have a ghost Sylveon when you could have a ghost type eeveelution, but I like the idea.