Evelynn Idea (For Now or Rework)

So one of her only cc's come from her ult, which is only a slow, so I was wondering what would be a good way to keep Evelynn sticking to targets without adding any oppressive hard cc.

My idea is esstianally Evelynn could break Speed Steroids. I feel like this could Proc of her E and could allow her to compete against a few more mobile junglers (Hec, Yi, other Evelynn's) while not giving her too much ganking power, since it would be mainly for sticking on a target or chasing one down.

For a list of Champ MS steroids it would effect here are

Summary: If E could kill MS speed steroids, how would that be?