Make sure you download both the resourcepack and the datapack.
This data pack adds new forms to Sylveon themed around various pride flags.
To obtain a Sylveon with this new form, right-click it with a Prism Scale (form chosen is random, if I had a good way to let you pick a specific flag I'd include it). This new form also learns a new move, "Stand Proud", which sharply raises your special attack with a chance to raise adjacent Pokemon's special defense.
Currently, the datapack has the following pride flags:
LGBT (the rainbow one), Asexual, Agender, Aromantic, Bisexual, Genderfluid, Genderqueer, Lesbian, Nonbinary, Pansexual, Polysexual, Trans, MLM
I am always open to adding more flags, so please feel free to suggest some if you'd like to see it (preferably put them in the "Issues" tab so I can keep better track of them)!
Shiny forms are WIP, so for now they will just have the default look.