Quick Suggestion for a Syndra W Improvement

(This is pasted from a thread I responded to) Rioters had mentioned including a knock-up on her W. Heres a quick suggestion regarding the knock-up:

-(Before rank 5) Syndra throws her W, slowing all enemies hit.

-(After rank 5) Syndra throws her W, slowing all enemies hit. After a (?) second delay, the sphere pulses again knocking all enemies still within the radius slightly towards the sphere.

This should mostly force syndra to set up her combos still with E while not making the stun overly reliable with an instant W knock-up. Perhaps to compensate the increased slow duration could be altered/removed. Thoughts?