I know that Manaphy along with the Manaphy egg are both shiny locked, but no one said that Phione was shiny locked in particular. Even though it would be safe to assume that Phione IS shiny locked, a part of me still wonders. I looked online on like 5 different websites and just got the same "Manaphy is shiny locked", but nothing for Phione. So, do you think it's possible?
In this game, all Legendary Pokémon and the starters are not Shiny Locked. The only Shiny Locked Pokémon are the gift Jirachi and Mew from Floaroma Town, as well as the Mystery Gifts.
It is not shiny locked. You can get one by hatching eggs that have Phione in them.
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