This is a tricky topic, as it’s just as much of a debate within the research community as it is among trainers and the like. Nonetheless, I personally believe that because the only way a phione can come to be is through the mating of a mythical pokémon, this makes it mythical in a sense as well—just not, perhaps, by the strictest definitions. It’s essentially the equivalent of a demigod but a pokémon: admittedly not quite a legendary but certainly separate from a common pokémon.