The Heian Era in Jujutsu Kaisen was a period in ancient Japan often regarded as the golden age of jujutsu, roughly a thousand years before the modern storyline. Curses and sorcerers were far more powerful and numerous than in the present day, and society was deeply influenced by supernatural forces. Powerful jujutsu clans and sorcerers competed for influence, while battles between humans, curses, and sorcerers were frequent and brutal. The era was chaotic, violent, and dominated by individuals who possessed extraordinary cursed energy and techniques. At the center of this age stood Ryomen Sukuna, a legendary sorcerer who became known as the King of Curses. During the Heian Era, Sukuna was not merely a curse but an overwhelmingly powerful human sorcerer feared by virtually everyone around him. He possessed immense cursed energy, exceptional physical strength, extraordinary combat ability, and a terrifying innate technique. His reputation was so overwhelming that other sorcerers regarded confronting him as nearly suicidal. Sukuna lived according to his own desires, showing little concern for morality, authority, or the lives of others. He became the ultimate symbol of the Heian Era's brutality and the pinnacle of jujutsu power, leaving behind a legacy that would still terrify sorcerers a thousand years later.