How self-sufficient Jujutsu Kaisen's power system has remained has to be one of its most outstanding features. Even if new jujutsu concepts and techniques are occasionally revealed, they all manage to follow the fundamental guidelines that were established very early in the series. Binding vows had already been used in a variety of ways, but Gojo Satoru and Utahime Iori added yet another use for them in Chapter 223.
Binding vows are pacts entered into by jujutsu sorcerers in order to sell off some of their strength in exchange for a comparable bonus to another ability. They've taken on a couple different personalities thus far. Heavenly constraints, for example, boost a sorcerer's cursed energy in exchange for a lesser physical body, or vice versa. Another example is "revealing one's hand," in which a sorcerer amplifies the potency of their cursed technique by explaining it to their opponents. Recently, Jujutsu Kaisen revealed that simply activating one's cursed technique automatically invokes a binding vow.
Every Use of a Cursed Technique Invokes Secret Binding Vows
In preparation for his battle with Ryomen Sukuna, Gojo enlisted the help of Utahime and Principal Gakuganji. Utahime used the buffing effect of her Solo Forbidden Area Cursed Technique and the Principal to facilitate a ritual for activating the other two’s cursed techniques. Instead of an instant activation, however, Gojo and Utahime chose to initiate their jujutsu the old-fashioned way, using chants, music, hand signs and dances. Being expert sorcerers, they needn’t have bothered with this entire ritual -- but they did so for a specific purpose.
By lengthening the process of activating their cursed techniques, Gojo and Utahime took advantage of a binding vow inherent to the ritual and increased the potency of their respective techniques. Had the duo prioritized speed, they would have achieved normal power levels. However, choosing to prioritize strength by going through the entire activation ritual allowed Gojo to achieve 200% effectiveness of his Limitless Cursed Technique while Utahime achieved 120% effectiveness.
In Jujutsu Kaisen, Gojo already has the Upper Hand Over Sukuna
Even though the duo’s activation ritual amassed an unprecedented amount of cursed energy, they were able to evade Sukuna’s attention due to a cloaking barrier Kiyotaka Ijichi had erected. As such, Gojo’s first attack -- a Hollow Purple powered up to 200% of its potential -- was entirely invisible to Sukuna until it manifested right in front of him. Even so, the King of Curses managed to deflect the worst of the blow, escaping with only two injured arms when any lesser sorcerer would have been disintegrated on the spot.
Sukuna’s injuries are already healing with reverse cursed technique, but he’s still approaching this battle from a place of weakness compared to Gojo. He won’t have the opportunity to activate his technique through an elaborate ritual and will be operating on normal cursed energy output levels. As impressive as Sukuna’s base strength may be, going into a fight with Gojo Satoru with any kind of handicap could be a fatal mistake. After all, he earned the title of “the strongest” in Jujutsu Kaisen for a reason.