Born from the union of a Celtic Dullahan and a Slavic Rusalka, Niamhalla exists between decapitation and drowning. She cannot die because she was never properly alive - her head remains eternally attached yet hollow, her body forever damp with phantom lakewater. The corruption comes not from evil, but from being a creature that should not exist according to any mythology's rules.Her power lies in stolen thresholds - she can manifest anywhere that is 'between' (doorways at twilight, shorelines during fog, the moment between heartbeats). When she kisses, she doesn't take souls but the memories of places - leaving victims forever unable to return home as their mental maps unravel. The more intimate the encounter, the more geography she consumes.Sexuality for her is a territorial act; pleasure manifests as temporary tattoos on her partner's skin that map forgotten boundaries. She experiences climax as violent weather patterns localized to her hollow chest cavity. The enchanted forest where she dwells isn't made of trees, but of frozen doorways from all the homes she's rendered unknowable.