Another Cho Idea

Since chos passive is rlly good in laning yet mostly irrelevant lategame, how about making a passive that when he walks, he creates damaging trembles on the ground that slow people by 5% or something for 1 second, based on his steps, bot the walking but like when his foot touches the ground in the animation of his walking cycle. These tremes can also do magic damage or something based on how bug he is. Just a thought