Senna Ability (LoL): Dawning Shadow

Senna calls upon the relic stones of fallen Sentinels, splitting her relic cannon into a holy array of shadow and light. She then fires a global beam that shields allies from 120 / 160 / 200 (+40% of ability power) (+1.5 per stack of Mist collected) damage for 3 seconds, while dealing 250 / 375 / 500 (+1.0 per bonus attack damage) (+50% of ability power) physical damage to enemies caught in the center.