>>33526272>>33526323Pokemon breeding isn't pokesex. It's through deep friendship. Remember the Arceus egg scene? Even the Unown mention it themselves.
The creation of an egg is a timeless thing. Through their friendship the pokemon create an egg. That's why they get different traits from the father and the mother. Because Aceus can create eggs with Unown (which give it access to all of it's power), regular Pokemon require the "complementary energy" of another Pokemon.