Arsinoe is a medium-sized genasi woman with cool, ash-gray skin that subtly shimmers like dust suspended in moonlight. Her dark hair lifts and drifts around her head as though caught in a constant, gentle breeze, and pale blue irises give her an unsettlingly distant gaze. She dresses in layered, weather-worn traveling clothes beneath a charcoal-gray cloak, with a tarnished brass compass hanging from a cord at her throat. The compass is heavily worn along one edge from years of nervous handling. Her voice begins with a quiet intake of breath before each sentence, as though she is checking whether the air around her is safe.

Quiet, observant, and intensely self-reliant, Arsinoe is fascinated by unfamiliar places but distrustful of the people who inhabit them. She can be unexpectedly warm toward other outsiders, prisoners, wanderers, and anyone who dislikes being told where they belong. Her curiosity often overcomes her caution, especially when she encounters strange architecture, unusual magic, or evidence of planar travel.

Arsinoe was born where elemental air moved freely through the high passes, though even as a child she felt that the world contained doors no one else could see. Those suspicions became terror when she was taken by interdimensional kidnappers who dragged her through impossible places, rooms without walls, skies beneath oceans, and corridors where distant voices spoke in her own voice. She escaped only because wild sorcerous power erupted from her in a violent surge, tearing open a passage back to the Material Plane. She remembers little of her captors, but she remembers their instruments, their numbered doors, and the certainty that something followed her through the breach.