Dione Nephilim is a gigas, a rare giant species residing near a harpy village within the coexistence city of Lindworm. Her last name stems from the biblical Nephilim, hybrids born from unions between human women and fallen angels known as Grigori. Though considered young for her race, she is hundreds of years old and possesses an exceptionally long lifespan, capable of sleeping for 10,000 years without adverse effects. She has known other long-lived beings, Skadi Dragenfelt and Cthulhy Squele, for a significant period; her friendship with Skadi dates back at least ten years, to Lindworm's founding as a coexistence city.

Her gigantic body far exceeds human scale, requiring scaffolding to interact with her head even while seated. She possesses notable strength, lifting humans effortlessly. Unintentional actions like sneezing generate considerable force, enough to blow individuals into trees. Long green hair reaches her hips, and her eyes remain consistently hidden from view. A gentle and sweet disposition defines her personality. She moves carefully to avoid harming small creatures underfoot and exhibits wisdom and compassion, earning respect from her people. While generally calm and collected, she displays occasional stubbornness.

Approximately ten years prior, coinciding with Lindworm's earlier era as a city primarily for mythical creatures and humans, she contracted an illness requiring medical attention. Dr. Glenn Litbeit treated her for a head cold during examinations at the harpy village. Her immense size complicates daily life, causing earthquakes and landslides with each step, necessitating slow and deliberate movement to minimize environmental damage.

Her relationships include a longstanding connection with Skadi Dragenfelt, suggesting a significant friendship. She is also friends with Illy, a harpy who visits her mountaintop residence. Her species' characteristics and personal history integrate her into Lindworm's societal fabric, reflecting its themes of coexistence.