In ancient history, Sukuna was an enemy to the Yamato family but was also worshiped by some as a deity, though his association with demonic imagery was formed after the Imperial House of Japan declared him a vicious force of nature.

[8] Though Yuji has full control over his body, he is targeted for execution due to the danger Sukuna poses, with Satoru Gojo's patronage as his only protection.

In a mission to contain a Special Grade Cursed Spirit, Yuji and his colleagues are greatly endangered, so the young sorcerer gives Sukuna control of his body, to defeat his assailant.

Sukuna destroys the opponent, but seizes the moment of freedom to rip out Yuji's heart, and attempts to kill Fushiguro, becoming very interested in the latter.

He then saves Megumi from Mahoraga, his summoned Shikigami, catastrophically razing much of Shibuya ward in the process, before surrendering control back to a traumatized Yuji.

[12] Chingy Nea of Polygon praised the way Sukuna was a "cruel and emotionless sadist" and how he helped the anime "feign predictability" by having him kill Yuji early on in the story.

"[15] The character and Chase's performance in the dub was praised: "[he] lights up the screen as a newly incarnated Cursed Spirit, Ryomen Sukuna, as an elated insatiable animal that takes pleasure in grazing on the fear and flesh of humans and fills Fushiguro with a sense of dread of what’s to come.

"[16] The character was also compared to Bleach's protagonist Ichigo Kurosaki and his Hollow persona due their parallels especially in his early appearances; such being young fighters who develop supernatural powers as well as evil alter-egos in order to protect people from giant monsters.