Since the introduction of Primal Regression was introduced I've been toying with the theory that any Legendary with a Mega-form instead of a Primal Regression, like Mewtwo, is an artificial Pokemon because they have no Primal form to regress too. Naturally this means Latios/Latias are artificial Pokemon.
The more I think about it the more sense it makes. They're opposite genders of the same species, totally unique among Legendaries (even the other ones with gender's don't have a distaff counterpart). Their bodies are based on jet aircraft, although admittedly that's a chicken/egg situation.
Then there's the Soul Dew. I always felt like most items associated with Legendary Pokemon were either things humans constructed to interact with them (like the Time/Space orbs or Ho-oh's bell) or things associated with them that exist naturally (like Shaymin's flower, the Black/White Stones or the Silver Wing). But the Soul Dew doesn't seem to fall cleanly into either of those categories, because the Eon's lore seem to treat the soul dew almost like a part of their beings like the Silver Wing, but it LOOKS like something man made rather than something that would ever occur in nature.
Note that artificial doesn't necessarily only mean man-made (though I do think this might be the case for Lati@s). The Legendary Dogs and the Golems were artificially created by Ho-oh and Regigigas, so they would have Mega forms instead of Primal forms as well.
