The daughter of a sawyer, Halissa and her family resided in Westmarch, in a village close to Tristram, located in a forest. She was close to Valla, and her face always lit up at the sight of her.
Halissa's family were killed by demons, when the Hellspawn attacked their village. Valla grabbed Halissa and they ran to the river and hid for weeks. Memories of the massacre gave her nightmares and "unhinged" her mind. One night she woke up screaming and ran, coming too close to the riverbank and slipping. Valla, who had chased after her, tried to grab her hand, but lost her grip and she was swept away in the current, raving and cursing before drowning. Her soul wound up in the Pandemonium Fortress. She looked for her parents, but couldn't find them. But she knew they were somewhere nearby. She could hear them screaming.
Valla erected a gravestone for Halissa beside the graves of her parents. She later joined the Demon Hunters, and kept an etching of her sister on hand, even two decades after her death. Halissa's death continued to haunt her, and the memories were used against her by the demon Valdraxxis. Just prior to her departure for Khanduras in light of premonitions of a Fallen Star, she visited Halissa's grave again.
Years after her death, Malthael led the Reapers against Sanctuary. Ordan instructed Halissa in the means to communicate with the living. Sure enough, Valla encountered Halissa within the Pandemonium Fortress. As Halissa explained, "something bad" kept her soul in the fortress, and asked Valla to remove it.
In Diablo III, Halissa appears within the Pandemonium Fortress in Act V, provided the player is controlling a Demon Hunter. The game operates under the premise of her being the sibling of the Demon Hunter, regardless of the character's gender (the same principle applies to the Demon Hunter's cinematic intro and journal entries). She is depicted as a little girl armed with a Hand Crossbow.
Her initial portrait found in the game files shows her as a young woman (not a girl) with similar facial features.
Personality and Traits
Valla described Halissa as possessing bright, inquisitive eyes, and boundless energy.