Glacial Augment

Immobilizing an enemy champion will cause 3 glacial rays to emanate from them towards you and other nearby champions, creating frozen zones for 3 (+ the immobilizing effect's duration) seconds that slow enemies for 20% (+90% per 100% Heal and Shield Power) (+6% per 100 Ability Power) (+7% per 100 bonus Attack Damage) and reduce their damage by 15% against your allies (not including yourself). Cooldown: 25s

Tree

Inspiration

Row

Keystone

In short

Immobilizing an enemy champion will cause 3 glacial rays that slow nearby enemies and reduce their damage to your allies.

Patch

16.16.1