>>50945069It's simple, anon. You sit them down, and you show them a mirror. And you say, "Like it or not, Sylveon, this is you. And that? That down there? That's your penis. Wearing panties and changing your pronouns doesn't change what you are. It doesn't change how the world perceives you. Instead of asking the entire world to pretend you're something you're not, why not simply accept yourself as you are, and learn to be appreciate of all that you have in life?"
Make sure that Sylveon is nowhere near the internet when you do this, though; if it can access the internet, it will get affirmation from other Transylveons online, and then it will post your personal details so they can harass and possibly murder you. This will obviously impede growth for the Sylveon, and make it impossible for the Pokemon to ever really love itself which can tragically end in death.