If 2 stacks of Grimheart are consumed upon unleashing the Holding Mode of Icetide Vortex, a Shattered Lightfall Sword will be created that will explode immediately, dealing 50% of the basic Physical DMG dealt by a Lightfall Sword created by Glacial Illumination.
Sadly she isn't a Geo Construct. Lumi better eat more Geo before she counts as one lol