Mythic versus Ultimate Skins vs Legendaries

Okay, so Riot -

I love to buy new Skins. I know that I'm not the only one... skins are obviously very popular.

One thing that I don't understand is the difference between Mythic, Ultimate, and Legendary skins. Considering how long it takes (and potentially how expensive they can be) to get Mythic skins, I would think that Mythics would have more effects and features that would be more aligned with Ultimate Skins. Instead they're more like Legendaries.

When I first got and played Hextech Annie, I was very disappointed. This skin is not nearly as awesome as I was expecting. But if I play using ANY Ultimate Skin I love them! I really like being able to change the skin in game depending on my mood or like Udyr, depending on ability.

Since Mythic skins are supposed to be exclusive, expensive, and hard to obtain, maybe they could be updated to reflect those principles.