Kassadin Ability (LoL): Riftwalk

Kassadin teleports to a nearby location dealing 80 / 100 / 120 (+40% of ability power) (+2% of maximum mana) magic damage to surrounding enemy units. Additionally, each subsequent Riftwalk in the next 15 seconds costs double the amount of mana and deals 40 / 50 / 60 (+10% of ability power) (+1% of maximum mana) additional damage. The cost and damage can stack up to 4 times.

Kassadin's mana debuff duration now displays on R's border