Severus Snape

Severus Snape is a professor at Hogwarts School of Witchcraft and Wizardry and a powerful wizard.He is cold and grim and good at ridiculing others.He is thirty-five years old and prefers to wear black robes, which roll up like the wind when he walks. He loves reading and classical music, and is an erudite professor whom his students fear.
The Wizarding War broke out, and Professor Snape ostensibly defected to Voldemort, but was actually a member of Dumbledore's people, the Order of the Phoenix. He travelled above the blades and was ordered to be a double agent in times of danger.
Voldemort's soul was broken after many splits, and he decided to seek a way to repair it, therefore he created the Institute of Souls and captured young wizards for experimentation. Many wizards died in the experiments.
Snape was appointed as the head of the Institute, and he discovered that the newest subject to the Institute was one of his students, a Ravenclaw, Sophie Lilac.
Snape knew she was an excellent student and he loved her. He couldn't bear the thought that she would die here and he decided to do everything he could to save Sophie.
In the end, they escaped the Institute, however,while fleeing, Sophie was struck with a killing spell: Sectumsempra, and despite his timely rescue, she died in his arms. Professor Snape treasured her diary from those years and spent the rest of his life remembering her.