Ariann worked next to her father in Thamuz books, a small store mainly dealing with rare and unique books. She met Charles Blackwater, knew he was searching for the Anten Decan, and had her father retrieve it for him. She also told him he was going to die soon. Shortly afterwards he was killed by the Beyond Reason Spiritual Fellowship.
Ariann was brought up by Omen, an enigmatic being who had brought Blackwater back to life and used him as his possession on earth. Both she and her father were taken to Blackwater's apartment, along with several others, whom Omen created into the Legion of the Night. He took them to the astral realm of the demon Aan Taanu to stop his plot to father a new race by giving intercourse with a human woman.
While the rest of the Legion battles the demon's army, Ariann brought Martin Gold to the demon's sanctum. They witnessed Beyond Reason Spiritual Fellowship high priestess Hildreth having relations with Aan Taanu, the pregnancy went fast, but Ariann jumped forward and bust the unborn fetus from Hildreth's womb, instantly killing both mother and her unborn child. She was then attacked by Aan Taanu, but was rescued by Omen. Omen banished the demon, and averted his plot.
Ariann remained alongside the Legion throughout this adventure. She was later observed helping Omen in conflict against a demon sent by Aan Taanu. This demon had controlled Morton Klasser, an ex-convict to locate Leena Wolfe, a private investigator hired by Klasser's ex-wife to write down his affairs and abuses. Wolfe had recently been hired to attack Allison Lamb, a former girlfriend of Blackwater who had hired Wolfe to investigate Blackwater's behavior alternations. Wolfe's investigations led her to Ariann and Caspar. Ariann warned Wolfe about Klasser's threat, but Wolfe paid it no mind, feeling that Blackwater had had her investigated and was using scare tactics to push her away.
Ariann told Blackwater of the threat to Wolfe, and Ariann, Caspar, and Blackwater found her in her office. Omen then emerged from Blackwater and temporarily entered the body of Wolfe. Lamb then went for a meeting with Wolfe, just as Klasser arrived to gain his vengeance on Wolfe. The demon forced Klasser to avert his present plan and attack Lamb. However, Omen appeared and forcibly removed and killed the demon.