Approach Velocity

Gain 7.5% Move Speed towards nearby enemy champions that are movement impaired. This bonus is increased to 15% Move Speed for any enemy champion that you impair. Activation Range for CC from allies: 1000

Tree

Inspiration

Row

Row 3

In short

Bonus MS towards nearby enemy champions that are movement impaired, increased for enemy champions that you impair.

Patch

16.16.1