Kai'Sa's basic attacks stack Plasma for 4 seconds, dealing 5 - 23 (+1 - 12 per Plasma stack) (+15/25% bonus Ability Power [based on Plasma stacks] ability power) bonus magic damage. Allies' immobilizing effects help stack Plasma. Additionally, Kai'Sa's item purchases upgrade her basic spells to have more powerful properties.
Enemies with 5 Plasma stacks are ruptured, consuming them to deal 15%(+6% per 100 ability power) of target's missing health as magic damage. Maximum 400 against monsters.