OVA
Description
Ais Wallenstein earned the epithet Sword Princess as a first-class adventurer and executive member of Orario's Loki Familia. Orphaned at age seven when the One-Eyed Black Dragon killed her parents, she joined the Familia, dedicating her life to vengeance. Her origins remain enigmatic—her father was a renowned human hero of the dungeon, while her mother Aria was a spirit, entities not typically capable of bearing children.

Early grief fueled self-destructive tendencies: neglecting her health, defying authority, and pursuing strength obsessively. Her vacant stare earned her the moniker "Doll Princess." Mentorship from Loki Familia executives—Finn Deimne emphasizing mental fortitude and technique, Riveria Ljos Alf guiding magical development, and Gareth Landrock teaching the necessity of rest—gradually tempered these extremes. Yet her profound hatred for monsters endured, frequently overwhelming her judgment when activating her skill Avenger.

Ais maintains a quiet, reserved demeanor, struggling to express emotions, which others often interpret as enigmatic aloofness. Mentally, she retains childlike qualities, visualizing a younger self during vulnerable moments like offering lap pillows to Bell Cranel. Her naivete manifests as gullibility; Loki easily deceives her, for instance claiming revealing attire enhances combat effectiveness. She harbors irrational fears, particularly of water stemming from a traumatic "swimming lesson" by Riveria involving adamantite weights.

In combat, Ais achieved the rare Level 6, specializing in monster extermination with exceptional strength, speed, and agility surpassing most peers. Key abilities define her prowess:
- **Ariel**: Wind-based enchantment magic usable offensively or defensively, manifesting as a "fortress of wind" at full power.
- **Avenger**: A skill amplifying attack power against monsters, especially dragon-types, scaling with her hatred. Its output damages weapons, limiting compatibility to durable blades like Desperate.
- **Spirit Healing**: A rare development ability regenerating her mind after magic use.

Relationships significantly shape her. Riveria acts as a maternal figure, guiding her since childhood. Though annoyed by Loki's perverse antics, Ais shares a mutually caring bond. She trains and is deeply admired by Lefiya Viridis.

Bell Cranel profoundly impacts Ais. Initially intrigued by his rapid growth, she becomes his secret mentor. Interactions with him evoke unfamiliar feelings: jealousy when others approach Bell, happiness during training, and fierce protectiveness when he faces danger. Memories of him persist even through magical charm or mental compromise, signaling deepening attachment.

The Xenos incident challenged her worldview. Confronted by sentient monsters like Wiene—who sacrificed herself for Bell—Ais questioned if all monsters deserved death. Though she initially fought Bell to reach Wiene, she ultimately accepted monsters could possess human-like hearts, resolving to define "monsters" by actions, not nature.

Her quest to slay the One-Eyed Black Dragon remains central, acknowledged as a selfish drive incompatible with heroism. This goal sometimes conflicts with personal bonds, like refusing Freya's request to aid Bell pre-war to avoid "rotting her sword" of resolve. Post-Xenos, she strives to balance vengeance with newfound empathy.