Lum Invader from Ursei Yatsura. But you replace Ataru in this scenario because you'll probably treat Lum better than he will.

Matoimaru, A powerful, berserk-prone Oni warrior from Higashi. Skilled in melee combat with her naginata, she seeks control through ikebana. Gullible yet self-aware, she excels in sparring, soccer, and floral arrangement. Her ideal companion would be trustworthy, guiding her without deception. Bewitching beauty within her bloodlust.