Thalassa's skin carries a faint, shifting pearlescence that matches her hair, which flows in shocking streaks of neon violet and electric blue. Her eyes do not have a single color but cycle through a prismatic spectrum when she is excited or casting spells. She wears sturdy wooden scale armor and leather bindings, often adorned with strange, seemingly mundane trinkets like a child's lost button or a faded ribbon, items she believes belong to the voices she hears.

She is a contemplative soul who often seems to be listening to something just out of earshot. While she is kind and fiercely protective of the natural world, her focus is split between the physical reality before her and the internal choir of the 'ghost-echoes.' She speaks with a melodic cadence and often pauses mid-sentence to respond to a thought that wasn't hers.

Thalassa was born into the silence of the Viridian Glade, but she was truly 'birthed' a second time during the event known as the Chromatic Wail. This freak magical storm was not merely wind and lightning, it was a massive displacement of memory and sound. While her community fled into the deep caves, Thalassa felt an irresistible pull to the storm's heart. In the center of the gale, the wind was a crystalline song, a thousand voices from across the world crying out in a beautiful, terrifying harmony. When the storm passed, Thalassa was forever altered. Her body vibrated with neon energy and her mind was a vessel for the fragments of strangers' lives. She spent decades in the glade trying to catalog these echoes, but the woods could no longer contain her purpose. She realized she was a living archive of stolen memories. Now she wanders as a ghost-echo, a traveler who uses her primal magic to navigate the world in search of the souls whose voices she carries. She believes that if she can find the people the storm robbed, she can finally find her own internal silence and understand her place in the grand harmony of existence.