Alex is a sworn soldier from Gallacia who uses the military-specific neopronouns ka/kan. A veteran who served for fifteen years, ka joined the army to support kan family and led charges during wartime. Pragmatic and observant, Easton travels to the decaying house of Usher out of deep concern for kan childhood friend, Madeline. Ka evaluates the eerie environment through a logical, practical lens while privately managing the lingering psychological trauma of combat.

Roderick is the fiercely anxious and physically deteriorating twin brother of Madeline Usher. He previously served in the Gallacian army under Easton’s command, an experience that established a lasting respect for the sworn soldier. Now isolated in his ancestral home, his physical and mental health rapidly decline as he desperately attempts to care for his ailing sister while refusing to abandon the rotting property.

Madeline is Roderick’s twin sister and Alex Easton's childhood friend. Having invited Easton to the estate because she believes she is dying, Madeline suffers from extreme anemia, bouts of catalepsy, and an inexplicable condition that causes fine white hairs to grow on her skin. She spends much of her time resting or making eerie, sleepwalking visits to the dark mountain tarn outside her home.

Miss Potter is a sturdy, pragmatic woman in her sixties who lives near the Usher estate. Though barred from official scientific societies due to the era's gender restrictions, she is a brilliant amateur mycologist and illustrator. She provides rational, grounded perspectives on the strange flora surrounding the area and refuses to be intimidated by the gloomy atmosphere.

Denton is a retired American military doctor with silvering hair and a mustache that is slightly too long for current fashion. Though his medical experience primarily consists of performing battlefield amputations rather than diagnosing complex illnesses, he remains at the Usher estate out of genuine concern for the twins. He connects with Easton over the lasting psychological impacts of their respective military service.

Angus is Easton’s deeply superstitious and fiercely loyal batman. Having previously served Easton’s father, Angus remains devoted to Easton in civilian life. He maintains a thick Scottish brogue when it suits him and views the dilapidated house with intense suspicion, actively avoiding the strange wildlife and trusting village rumors about witchcraft.

Hob is Easton’s trusted horse, brought along on the journey from Gallacia to Ruravia. Easton deeply values Hob's companionship and relies heavily on the animal's natural instincts, noting when Hob reacts with unease to the sinister environment surrounding the estate.

Alice was Madeline Usher's maid who died by suicide a few months prior to Easton's arrival. Her tragic death casts a long shadow over the estate, further contributing to the oppressive, grief-stricken atmosphere that permeates the house.

Aaron is one of the few remaining servants employed at the house of Usher. Despite the gloomy and dangerous conditions of the rotting house, he continues his duties and maintains the property's logistics.

Mary is a servant working at the dilapidated house of Usher. She endures the frightening environment alongside Aaron to keep the household functioning for the ailing twins.