Warning! Spoilers ahead in Jujutsu Kaisen chapter 175!
One of Jujutsu Kaisen's most defining qualities is not only its use of creative and complex techniques but how the manga continues to innovate them in appealing ways, heavily augmented by mathematical formulas - and Yuta Okkotsu just did so in the grossest manner imaginable.
In chapter 175 by mangaka Gege Akutami, Yuta Okkotsu alters the reverse cursed technique that's normally used for healing to exorcise the cursed spirit Kurourushi by giving him mouth-to-mouth, shooting the reversed energy directly into its brain during the Culling game. The purpose of jujutsu sorcerers is to exorcise cursed spirits that manifest from the negative emotions of mankind, but, ironically, these sorcerers have always accomplished this by leveraging the actual composition of the curses themselves to eliminate them. Since a curse is composed of bad emotions, it's understandable Akutami later reveals that this energy is negative.
But Akutami doesn't just rely on one definition of the word negative when applying this type of energy to emotions, which, in this particular context, obviously signifies hatred or greed, for example. He associates this type of energy with the scientific phenomenon where a charge or voltage is less than zero. So, when the mangaka later introduces a phenomenon where jujutsu sorcerers can reverse this type of energy into something positive, he naturally applies the scientific definition that means an energy source that's greater than zero. Of course, Akutami focuses on the more numerical side when he describes this process of reversing cursed energy into something positive by using a mathematical formula. Essentially, jujutsu sorcerers must constantly multiply their negative energy until it finally becomes positive, hence why few jujutsu sorcerers have mastered it. But since this energy is positive, Akutami also embraces the emotional quality behind the word, moving away from the bleakness of curses by creating a phenomenon that heals rather than destroys.
But because cursed spirits are composed of negative energy, it makes sense that these reverse cursed techniques, which generate the opposite type of energy would hurt them. However, Akutami decided to avoid simplifying this phenomenon by, for example, having positivity naturally eliminate anything composed of negativity. In chapter 175, Yuta is only able to come up with this positive-beats-negative strategy based on an earlier moment when he forcibly pushed positive energy into Yuji Itadori to jumpstart his heart. Since positive energy doesn't naturally destroy, even against something wholly composed of negativity like a cursed spirit, Yuta realizes that the only way he can repurpose a healing technique into an attack is if he forcibly pushes that energy straight into the brain of a cursed spirit. Yuta accomplishes this by giving his cursed opponent mouth-to-mouth, shooting the positive energy into its brain.
This isn't the first time that Jujutsu Kaisen has revolutionized the reverse cursed technique. Earlier, mangaka Gege Akutami delved beyond the signification of the words positive and negative by focusing on the word reverse. Instead of this technique just switching the energy from positive to negative, Akutami had Satoru Gojo reverse a technique called Limitless when he combines the two. The end result is that instead of creating a magnetic effect as is the norm, the reversed Limitless creates a repelling effect. It's extremely likely that Yuta or another character will revolutionize the reverse cursed technique once again before the series ends - just like every other technique in Jujutsu Kaisen.
