Sorcery Rune/Keystone Concept: Frost Bitten

Frost Bitten: Impairing the movement of a champion gives you a stack of collecting cold. At 3 stacks your next movement impairing ability will expunge the stacks dealing x damage over 3 seconds and increasing the crowd control affect by 20% if the ability used is a DOT the damage is doubled. Cooldown 15-5 seconds based on level.

Just another Keystone concept, seeking feedback. The goal with this one was to provide a decent rune for dot users as well as giving control mages some strength with the negative tenacity. It wont be as strong damage wise compared to others but its damage is split with its utility. Still strong on DoT users tho. Still working on a keystone for Precision and Resolve. My keystone concepts for Inspiration and Domination are done though.