I have enough other work to do on this wiki project than helping you in removing categories, that you messed up with, so don't tell me what to do right now and start removing those useless categories from Pokémon articles that you've added, for sake of registry of this project.
Just for you to know and to motivate you to delete those categories, here is my explanation how adding categories from Pokédex entries to categories of Pokémon articles affects registry and how redundant such categories are.
So as you can see in filter bar (top-right corner of attached pic) there are over 141 categories that completely waste this project.
No! Don't add Available Shiny Pokémon, especially not manually! 99% of categories for Pokémon articles are generated by template with Infobox for these articles, so don't add anything extra to categories unless you want to delete them all.