Giosuè - Master of the Spear

Easily Perlachio's most aloof student, she was already and excelled assassin before she joined his ranks.
Never really getting along with the other students, she was prone to leaving for extended times to give retribution for this or that grievance. After receiving Perlachio's tutelage, she made it a point to start hunting down powerful ascended beings, seeking to slay self-made gods and tyrants.
After one of her treks started stretching into decades, Perlachio and several of his students went looking for her. They found her on a world of night as a thrall of a vampire god. The god was so powerful that freeing her was a major challenge for the small group.
Once free and worlds away, she still felt the tug of her master. This was the deciding factor in Perlachio deciding to aid his students in building a powerful artifact for their selves.
She was definitely changed in nature as well. Where once she was driven to avenging wrongs and righting disruptions to nature, she now had an evil bent, not quaking at causing suffering for the greater good. She became the embodiment of the idea that several minor acts of evil were justifiable in the grand scheme if some great evil could be defeated. For her, love became a useless emotion.
The weapon she chose to make was a great spear of power which she aptly named the Godkiller. With it, she once again returned to the world which still laid claim on whatever was left of what she called a soul to take down the vampire god. Again she failed, he lived in the world, but apart, existing in a mirror dimension.
Her power now was great enough that she began wresting control of several of the vampire lords on the world away to her servitude and was now leading large armies herself, enough so to challenged the vampire god for control of the world.
During this time, she returned briefly to Perlachio seeking to understand mirror magic. Begrudgingly, he taught her the secrets he knew of the craft. He was not happy as he felt she betrayed herself constantly by using her vampire gifts which relied on the need for mortals to be cattle in feeding her constant hunger.
When she returned for a third time, she was able to enter the actual domain of the vampire lord and slay him. After that, she set herself up as the ruler of the world of vampires and began using her armies to hunt down powerful beings on other worlds.
She would never be seen or heard from again except for the final meeting of the students.