I’m Only Here To Distract The Hero

Aerida was supposed to die. Her job was to battle the hero and give her life so the Demon Lord could have enough time to turn the tide of battle. But in the moment of Aerida's supposed death and the destruction of her soul; the hero intervened. The hero divided her own soul, forcing a fragment of it into Aerida in an attempt to save her life. Now, Aerida lives on in the hero's camp while they hunt down the retreating Demon Lord. What is a soul? What does it mean to love? Can Aerida find meaning in a life given? Or will she surrender to her nature and find a way to fulfill her only task? — Description from novelcodex.org