SUNBURST: Your ability casts generate a stack of Radiance lasting 10 seconds, refreshing on subsequent casts and stacking up to 3 times. Each unique ability counts once every 2 seconds.
Basic attacks that critically strike will consume a stack to deal 38 − 80 (based on level) bonus magic damage on-hit. This damage can critically strike.
Each unique ability can only generate a charge once every 2s.