Kiana Kaslana began as laboratory test subject K-423, a synthetic lifeform engineered in facility eA-401-435. Her creation utilized genetic material from the original Kiana Kaslana and the Herrscher Sirin, with the core of the 2nd Herrscher implanted within her. Siegfried Kaslana rescued her from Schicksal, initially keeping his distance before fully accepting her as his daughter once she embodied the Kaslana family's protective values. He formally named her Kiana Kaslana on her eleventh birthday, imparting the family motto: "fight for all that is beautiful in the world." Her early personality was marked by boastfulness, recklessness, and a lighthearted nature, including a pronounced love for food and open romantic affection for Raiden Mei. She trained as a Valkyrie at St. Freya Academy, where her combat prowess starkly contrasted with her academic struggles. The traumatic awakening of the Herrscher of the Void within her during the 4th Honkai Eruption drastically altered her demeanor, leaving her guilt-ridden and prone to self-sacrifice. Fearful of harming others, she isolated herself, sometimes masking her distress with forced cheerfulness around Mei. Key relationships profoundly shaped her. The bond with her mentor, Murata Himeko, served as a vital emotional pillar; Himeko's sacrifice to save Kiana from the Herrscher of the Void shattered her but ultimately reforged her resolve to honor Himeko's legacy. Her foundational connection with Raiden Mei endured; Mei's departure to World Serpent to save Kiana's life initially caused conflict, but Kiana later understood Mei's choice, solidifying their partnership. Kiana waged internal battles for control against the Herrscher of the Void within her consciousness. Accepting that both her identity and the Herrscher's were manifestations of Sirin, she defeated the Herrscher persona during the Theatre of Domination, gaining full authority over her Void powers. She subsequently awakened as the Herrscher of Flamescion by synthesizing her Void abilities, the Gem of Haste inherited from Himeko, and elements from Bronya Zaychik's Reason and Fu Hua's Sentience authorities. In the game's finale, Kiana ascended as the Herrscher of Finality after receiving acknowledgement from the Cocoon of Finality. This granted her authority over all previous Herrscher powers, which she used to permanently halt the Honkai threat. To contain the Honkai energy and protect Earth, she accepted self-imprisonment on the Moon. From this role, she watches over humanity as a guardian, occasionally reuniting with friends in limited ways. While her earlier cheerfulness resurfaced, it is now tempered by maturity and responsibility. The non-canon "Cooking With Valkyries" spinoff depicts her everyday interests, showcasing her enthusiasm for food preparation and shared meals, reflecting her lighter traits without advancing her core narrative.