Miyazaki Seine is a 300-year-old girl with an immortal body who Tatsuya invites to live in his home. Before that she lived in a cardboard box in a park. In the first episode, Seine looks like a masochist because she seems to like being bullied. Actually, she becomes close to people who are infected by "mushis", a kind of parasitic, mind-controlling bug, in order to hunt them. Her hunting ways go against the kind and pacifist Tatsuya's beliefs. Her motive is to avenge her foster father Shimon's death by killing the people of sea, the mermaids. She controls a black snake called Aion that lives inside her. Tatsuya at first calls her "Miyazaki-san." She tells Tatsuya to call her "Seine" since "Miyazaki" is just made up. "Seine" merely sounds most like her real name. She claims to only love Shimon, but she is slowly warming up to Tatsuya.
Powers and Stats
Tier: 9-B with Aion
Name: Seine Miyazaki
Origin: Hekikai no AiON
Age: 330+ years
Classification: Human, Witch
Attack Potency: Wall level with Aion
Speed: Hypersonic with Aion
Lifting Strength: Unknown
Striking Strength: Wall Class
Range: Kilometers (Aion can be extended several kilometers)
Aion - A cross between a symbiote and a familiar. Aion - a kind of demonic entity that looks like a black long snake. He can be extended for several kilometers and to move at hypersonic speed. In addition, it is very flexible, as it can easily change its shape and increase in size (may increase the head so that the person swallowing easily). Aion is related with the Seine's soul, so, even though he gives it immortality, she will die if he is used too intensively (more precisely, her soul will die, but not the body). In addition, the Seine die if something severs its relationship with Aion.
Weaknesses: Can't swim
- Communication - Seine telepathically connected with Aion. To manage him, she does not need to make any gestures or utter specific words. In addition, Seine shares Aion's feelings. Because of this she can "see" the goal, even at a great distance and get into a mermaid, which is located at a depth of 3 km deep in the sea.
- Empathy - Seine is able to communicate with the consciousness of mermaids and their victims, provoking a surge of emotion. Other words, she takes over their hatred. Although not a physical connection, if she hurts in the world of illusion, then she will get and the very real damage.