Implicating shadow_lugia → lugia
Link to implication
Reason:
Shadow Lugia, also known as XD001, was originally a Lugia before being corrupted into a Shadow Pokémon. Unlike other Shadow Pokémon in the Orre games, Shadow Lugia's colouration vastly changes to a dark variant.
While there are images of other Shadow Pokémon with the same colouration scheme, (which should possibly come under a 'Shadow_Pokémon' tag) Shadow Lugia is canonically the only one to have such a colouration.
On a side note, if there is a Shadow_Pokémon tag, it should be considered separate from the alternative_color tag.
Edit:
I have since agreed that this implication is not needed.
Updated