Lethal Tempo

Attacking an enemy champion grants you [6% Melee || 4% Ranged] Attack Speed for 6 seconds, up to 6. At max stacks, deal [9 - 30 Melee || 6 - 24 Ranged] bonus adaptive damage On-Attack, increased by 1% per 1% Bonus Attack Speed.

Tree

Precision

Row

Keystone

In short

Attacking an enemy champion grants you Attack Speed, up to 6 stacks. At max stacks, deal bonus adaptive damage On-Attack.

Patch

16.16.1