Eclipse

Unique – Ever Rising Moon: Damaging basic attacks, abilities, item effects, and summoner spells, as well as the application of crowd control and damage over time effects, generate stacks against enemy champions, up to one per attack or cast per champion. Applying 2 stacks to a champion within a 2 second period deals bonus physical damage to them equal to (6% / 4%) of target's maximum health and grants you a shield for (160 / 80) (+ (40% / 20%) bonus AD) for 2 seconds (6 second cooldown).

Limited to 1 Eclipse.