Jujutsu Kaisen is part of Shonen's Dark Trio, and it follows a group of powerful jujutsu sorcerers. These sorcerers are usually humans who are trained and employed by the Japanese government to protect humanity. The majority of jujutsu sorcerers are capable of using cursed energy, and they often use their abilities to exorcise cursed spirits. Every jujutsu sorcerer is supernaturally proficient, but there is a grading system that ranks every sorcerer based on their skill level. The rankings ascend from Grade 4 to Grade 1, but there are certain individuals who hold the Special Grade rank.
Source:https://www.cbr.com/every-special-grade-sorcerer-in-jujutsu-kaisen/