"Hiding out in the soul society is a lot more peaceful than I thought"
Isperia, at the best of times, is very warm hearted and helpful despite being an arrancar. Normally taking up odd jobs and sleeping in vacant houses or in the gardens at Shin'o academy; she make it a habit to either try and help out in the guide of a resident or another student. However, she is rather aloof when asked where she came from or where she live since she doesn't really have a home in the soul society.
In Hueco Mundo, her demeanor changes from being warm and playful to serious from being on guard due to being a target for many hollows in the area. Though she is still helpful to others if they are genuine and if they are another arrancar or a Vasto Lorde.
Memory of Isperia's past is vague to her, but she was murdered on her way home from work by a hollow and became one herself. She wandered Hueco Mundo alone, devouring and fighting other hollows that challenged her and befriended those that came in peace. Over enough time and devoured hollows, she became a Menos Grande and very quickly became an Adjuchas on her own right.
During this time, she had become tired of the fighting, but found it unnecessary to survive the harshness. Many of her companions either fell to other hollows or turned on her to try to gain her power. By the time she had become a Vasto Lorde, she had started to wander near Las Noches. She was recruited by the arrancar of Las Noches and turned to the form she is now but still was unhappy with the coldness of the others.
Isperia quietly defected and started to wander between worlds, often going to the soul society in secret and blending in with the locals there. Only every now and again will she return to Hueco Mundo to find any of her kind that are of like mind.