The Blade of Evil style involves utilizing every part of the claymore, including the hilt and cross-guard, in attacking the opponent. Uranus created it to compensate for her lack of speed and physical strength when fighting stronger opponents. Her area had a lot of Awakened Beings, and this sword style was her means of survival.
Other Claymores looked down upon the style, calling it crude and desperate. Roxanne, however, was smitten with the technique because of its ingenuity and practicality. She befriended Uranus and began to imitate her fighting style, causing the two to become closer. Later, when Roxanne's power exceeded Uranus's, she grew to hate both Uranus and the Blade of Evil. It was shortly after that Uranus died in an Awakened Being hunt.