Sion change for ult

I guess this would overall be a buff, but here it goes. What if the hitbox on Sion's ult increased with how far he traveled? Make it about have the size it is now when he first activates it, then 25% bigger than it currently is towards the end of it. This was just a thought I had about it because later in the game with how much mobility a lot of champions have these days and the introduction of the new hextech rocket boost item, this could help our undead friend out. Now, the numbers I posted are simply for example.