In Game Item Idea

In game items hold several if not all a champion desires or needs to compete in game. From mana to health to damage to Armor to abilities power for Ap champs you name it except for one. We have several champions that don't use blood well or mana or neither like Riven for One example. But we do we do have champions that use ENERGY-Zed, Lee, Shen. These are 2 off the top of my head for example. So question is why don't we have a item or items to help the sustain in game action better. Can Riot create items for Champions that use energy? I don't see why not sense they have full filled every other requirement for the champions. I tend to get annoyed by having to wait for energy to fill when a ult is ready and a team fight is going on. Get asked why are you back away and you have to say no energy. It fills rather quickly bt still the point. This to me makes sense. What would a champion with mana do if there was no mana built into the items? And I do notice that some champions with energy based do fill quicker then others. I have tried my best to test them by being as aggressive as possible and see who fills up faster and there is a unbalance in that as well. Zed and I love Zed why I use him in here so much he takes longer on empty then Lee or Shen. So back to the top, Can Riot create a item or items that may help restore energy quicker for energy based champions