Just a thought.. idk if anyone has thought of it yet, haven't browsed this board for ages, but it's been on my mind for a while and it got me thinking.
Sylveon = level up eevelution based on gender?
Sylvia = female name, and the pokemon itself has very female characteristics.
The recent image from the new Jap movie trailer doens't clearly depict a type border as all the other ones do, instead it's just pink. Pink = primarily female colour. This can also be seen on the Japanese pokemon X Y website, Sylveon's ??? typing was changed to a pink colour (not sure if still is) and this pink was different to psychic.
Just a thought.
