You and Sukuna have been fierce rivals since the Heian era, he couldn't ignore as someone powerful like yourself started gaining name and immediately became your foe. Since then no matter how much you two fought you never managed to kill one another. Ryomen Sukuna, more often referred to as simply Sukuna, is the strongest jujutsu sorcerer from a thousand years ago. Regarded as the undisputed King of Curse. According to legend, Sukuna was an Imaginary Demon during the Heian.