The undisputed King Of Curses, Ryomen Sukuna is one of Jujutsu Kaisen's most iconic and recognizable characters. His origins date back to thousands of years ago when he was known as one of the most powerful jujutsu sorcerers. Sukuna also has had many enemies who wanted to destroy him, but he was too strong and was feared by many.
However, one day his enemies came together to defeat and execute him, this is when Sukuna split his powers into twenty cursed fingers and scattered them in various locations, causing him to go dormant. When Yuji Itadori comes across one of the fingers and swallows it in the heat of a battle, Sukuna was reawakened as a cursed spirit but was stuck in Yuji's body, thus making Yuji a vessel for Sukuna, possessing his body when needed.
Personality
Sukuna exudes an air of extreme pride and arrogance as he is fully aware of his immense powers and revels in it, this arrogance stems from his belief that he is superior to both cursed spirits and humans. He is also seen to be abnormally sadistic in nature, taking delight in the torment and sufferings of others, especially those weaker than him. Sukuna also does not hesitate to inflict pain on those deserving of it and also enjoys dominating them in the process. Underneath all this arrogance and pride, Sukuna is also known to be cunning and strategic to get his own way, this is seen when he switches with Yuji, but then rips Yuji's heart out to keep him from coming back so that he could take full possession of his body but fails to do so as Yuji takes back control, this results in Sukuna forcing Yuji into a binding vow.
Despite his evil ways, Sukuna also believes in displaying a certain code of honor and respect. He believes in keeping a promise and values the strength and skills of a person if they deserved it, acknowledging them even though he could easily overpower them. Sukuna also has a mischievous and malevolent side as he also takes pleasure in taunting his opponents, savoring the confusion and fear that takes over them because of the powerful presence he has. He also goes as far as toying wit his own vessel Yuji, refusing to help him when he is faced with a powerful opponent. The unpredictability of Sukuna's character is also seen throughout the series as it is difficult to predict his next move because of his enigmatic personality.
Being the king of curses, Sukuna fears no one, this is seen when he calls out Gojo, stating that he is capable of killing him. Sukuna is aware of his power and is not just merely calling out one of the most powerful jujutsu sorcerers of the current era but knows if given the chance, at his full strength, he does stand a chance of going up against Gojo.
Cursed Energy and Abilities
As a legendary sorcerer during the Golden age of jujutsu, Sukuna was feared by most of the powerful sorcerers and was able to defeat and kill thousands of jujutsu sorcerers who dared cross his path. This left many authority figures afraid of him while also earning himself the title - strongest sorcerer in history. Sukuna possesses an immense amount of cursed energy with the power to use it effectively, his ability to harness the vast amount of cursed energy combined with his physical strength made him a force to be reckoned with. His physical strength surpasses any normal human and his master hand-to-hand combat ability is extremely powerful. He uses martial arts to effortlessly overpower opponents in close combat unleashing powerful blows and powerful attacks. This is seen during his fight with Megumi, as he effortlessly almost defeated him with close range attacks before Yuji took over his body again.
Sukuna also possesses regeneration abilities that allow him to heal any injuries, he does this by using a reverse cursed technique to either grow back lost limbs or heal himself, this is seen when he regenerates Yuji's arm to stop a finger bearer from attacking him. He is also able to regenerate from more fatal attacks making him an opponent who is impossible to kill. Sukuna's speed and reflexes is also insane as he is able to move at overwhelming speeds and dodge attacks with ease. He is able to move so fast that even his opponent is unaware of the attack until the damage has already been done, this is seen when Sukuna cuts off the arm of the finger bearer before it even realizes what had happened.
Sukuna also uses different types of attacks such as dismantle which is a powerful slashing attacks that can be used against cursed spirits slashing them into pieces, he also uses a similar attack known as cleave to cut down a cursed spirit with one powerful slash. Sukuna can also create and manipulate flames to use as long-range attacks. In terms of defenses, he uses a domain expansion technique known as Malevolent Shrine which amplifies his cursed energy even more and guarantees a powerful hit on the opponent trapped inside the barrier.
Overall, Sukuna plays an important role in the development of the protagonist of the Jujutsu Kaisen series - Yuji Itadori and is instrumental in his growth. Sukuna's portrayal as a complex antagonist and an extremely powerful cursed spirit who captivates audiences with his unpredictable nature and mysterious persona.