For Immoble Mages: Item idea

So, I'm not a genius by any means, hell, can't even spell genius on my first try.

But,

So I was thinking about how mobility is so strong and more efficient than immobile champs most of the time, and what actually is the definition of 'mobility'. I came up with the idea that mobility is distance traveled in accordance to number of spells cast, at least when it comes to mages.

Because vel'koz presses a lot of buttons, as does vlad, but they dont move much outside of right-clicks. On the other hand, riven has movement built into two abilities, as does yasuo. So that's where my idea came from.

So my idea is if there is a way to create an item that benefits champs that move very little between casting abilities. I am not smart and I would have no idea how to code that, or anything similar, but if anyone reading this has an idea of how to make this concept work, i would like to hear it. Mostly i am jsut curious if there is a way to make this work.

And i just realized that there are ways to exploit my idea as well, but hey, I was just thinking