This is to confirm that nickname trick won't work with shiny when already used.

For something like Sunkern, of course its as simple as "Oh yeah, you can totally evolve this into a Sunflora, we just need 50 candies and a Sun Stone". Then there's Eevee, "Oh yeah, Eevee is great, you know what's even better? A Fire doggo. All you need is 25 candies and a Fire Stone. But wait, there's more, you could also get yourself a water doggo, but that's 25 candies and a Water Stone, not a fire stone. You know what? How about a Zappy doggo too? That's 25 candies plus a Thunder Stone. Not a Water Stone, not a Fire Stone, but Thunder Stone. Hey, how about them mystical psychic and dark doggos? Yeah, there's that buddy whatevers mixed in there somewhere"

/r/TheSilphRoad Thread Parent Link - i.redd.it