User blog comment:Willbachbakal/(Champion Concept) Rheya, Crux of the Elements/@comment-4068613-20130717205653/@comment-1330314-20130718003624

All abilities consume Rheya's existing charge and add one of their own. So past the first, each new spellcast within 10 seconds replaces Rheya's charge (except for her ultimate, which requires an existing charge but doesn't consume it).