|Partner(s)||Heads Hydra, Braz D. Blood|
|Family||Yanagi, Nyen, Hydra Bell, Hydra Knell, Heads Hydra, Yanagi Fuyumi|
|Debut: Anime||Episode 8 (silhouette)
Episode 9 (debut)
|Voice Actor||Japanese: Kotono Mitsuishi
English: Wendee Lee
Nyen is at once the mother of Fuyumi, Knell, and Bell. "Neyn" is the combination of two people, who fused once they met each other. Originally, one half was fully human, while the other was fully demon. They were totally separate beings, living totally separate lives, who had genetically unrelated yet still remarkably similar looking children, due to them being doppelgangers. When they merged, they combined memories, and became one being.
Nyen is a tall, beautiful woman, who often wears a black dress that exemplifies her bust. She has two mis-matched colored eyes, one being from the original Nyen, and the other from Fuyumi's mother.
Nyen is flirtatious and seductive woman, who isn't ashamed of her figure and in fact quite proud of it. Nyen is shown to care greatly for her family members, as she wished for Fuyumi to be back in her life again, and didn't want to leave either of her husbands when she fused. However, Nyen isn't above manipulation, as she hired Team Fearless to hunt down Staz just to be reunited with Fuyumi.
Her body includes both her and her "doppleganger", who is Fuyumi's true (and human) mother. She is married to Heads Hydra, and lives within his domain. She wishes to take Fuyumi as her own, however, does not seemingly succeed, despite having the help of Siam and Team Fearless.
Nyen so far, has shown no special abilities or powers.
Daughter: Yanagi Fuyumi
Daughter: Hydra Bell
Son: Knell Hydra
Husband: Heads Hydra
Husband: Yanagi (unknown first name)