Toggle: Anivia calls forth a driving rain of ice and hail, dealing 40 / 60 / 80 (+12.5% of ability power) magic damage per second to all enemies within while slowing their movement speed by 20 / 30 / 40% for 1 second and chilling them. Glacial Storm can be recast after 1 second. The blizzard increases in size over 1.5 seconds. At maximum size, enemies within the area take 300% damage and suffer a 50% stronger slow which lasts 1.5 seconds.
Glacial Storm deactivates if she gets too far away or runs out of mana. Additionally, Glacial Storm is deactivated by all forms of interrupting crowd control.
Once recasted, Anivia deactivates Glacial Storm, dealing one last tick of damage.
Costs 40 / 50 / 60 mana per second while the storm is active.