We've seen the battles of Jujutsu Kaisen: Mahito , including one with Itadori Yuji. At that time, Mahito's powerful spell had no effect on Yuji, the problem lay in the special things that Yuji had experienced.
Itadori Yuji is Jujutsu Kaisen's natural enemy: Mahito
Mahito's spell gives him the ability to reshape souls. He can shapeshift the bodies of his victims, heal his own wounds, turn his body parts into weapons, and countless other transformations. Mahito can even create a clone that can use Tasteless Transformation on himself. Therefore, he always recovers easily because what others attack is only his body, not his soul.
During the battle at Junpei's school, we saw Mahito try to use a spell on Yuji to transfer Sukuna's soul into his body and make himself the Uncle King's vessel. However, his calculation did not succeed. On the contrary, he was warned by Sukuna, so he had no choice but to fight Yuji directly. With a huge amount of magic and thanks to Wuwei transformation, Jujutsu Kaisen: Mahito is very confident that no matter how Yuji attacks, it will be useless.
The huge amount of spells made Mahito extremely confident
However, the blood spurting from his nose made Mahito realize that Yuji's body also contained another soul. He most likely understood the state of the soul and his attack could completely hit the soul directly. his soul, injuring him. Because of Sukuna, Yuji became his "natural enemy".
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Uncle King Sukuna did not like his authority being provoked
In addition to the possibility of Itadori Yuji directly sensing the soul state of Jujutsu Kaisen: Mahito, we also have another case because Yuji became the Uncle King's vessel. Sukuna is a solipsistic person who never likes others to challenge his authority. Mahito's spell tends to affect the soul, so when cast, it accidentally violated Sukuna's soul inside Itadori's body. He was immediately warned by Uncle Vuong.
As for Jujutsu Kaisen: Mahito , the power of his soul is like earth and sky compared to a king like Sukuna. When fighting Nanami and Yuji, he only used territory expansion to trap Nanami alone inside.
During the battle at Shibuya, too, Mahito knew that Sukuna did not like others touching his soul, so he opened his mouth to Uncle King immediately. He pledged to finish off Yuji when he guessed that Sukuna and Yuji had formed some kind of contract. Mahito also said he wouldn't let that happen so he hoped that Uncle Vuong would just watch. Thanks to that, when he used spells to attack Yuji, he was not punished by Sukuna.
Sukuna easily "killed" Mahito with just one blow
Although Jujutsu Kaisen: Mahito is a notorious villain in War Spell, it cannot be denied that he is an extremely attractive villain. His personality is brutal but childish, and he is also extremely intelligent and likes to toy with people's emotions. Hobiverse believes that Yuji will have to endure a long time when fighting this character.