For sorcerers and cursed spirits in Jujutsu Kaisen, domain expansion is the most potent ability. Despite the fact that many characters possess strong skills, only a select few have the ability to fully expand their domain. It is so powerful that using it more than once a day is impossible for users due to how much-cursed energy it expels.
Gojo Satoru, who possesses an infinite amount of cursed energy, is the sole exception to the rule. An individual who receives a special grade for a curse or sorcerer is on an entirely different plane from the rest of the population. The ability to use domain expansion is another thing they all possess. This raises the question of whether domain expansion is actually required to receive a special grade.
What Does a Jujutsu Kaisen Domain Expansion Mean?
The ultimate form of jujutsu sorcery is domain expansion. By using cursed energy to cast a barrier to create a different dimension or space, it enables a user to realize their natural domain. The opponent is consequently imprisoned inside that barrier and unable to escape. Each user of a domain expansion has a distinctive hand signal or another signal that must be used to activate the domain. The opponent is trapped inside, making it the strongest technique in Jujutsu Kaisen because it ensures the user's victory once it is activated.
The situation won't be reversed unless there is a unique situation in which the trapped opponent is also a domain expansion user. The more sophisticated domain will prevail over the other when two domain expansion users collide. In Season 1, Jogo activates its domain during the conflict between it and Gojo. However, a short while later, Gojo also activates his innate domain, making Jogo completely useless. Gojo won the conflict because his domain was more powerful.
Why Would a Domain Be Incomplete?
If the user is unable to fully form the barrier, a domain expansion can still be partially activated. As a result, the technique won't guarantee a hit, and the adversary might be able to escape. When the first-year students were dispatched on a mission to the juvenile center, that was the first instance of a domain expansion in Jujutsu Kaisen. Unbeknownst to them, a newly born special grade cursed spirit that was far superior to them was waiting there. They were caught in the realm of the curse as soon as they set foot in the juvenile facility. Nevertheless, as luck would have it, the special grade's domain was not complete.
None of the first years would have survived if it weren't for the incomplete domain. The Chimera Shadow Garden by Megumi Fushiguro is another illustration of an unfinished domain. His domain completely removes the restrictions on his innate Ten Shadows Technique, which is already extremely versatile. He can call forth an infinite number of Shikigami at once and even make duplicates of himself out of solid shadow using the Chimera Shadow Garden. These two domain expansions should not be undervalued, even though they cannot compare to the complete ones. Any domain, even one that isn't complete, gives the user a significant tactical advantage.
Does Every Sorcerer or Curse Have the Potential to Use Domain Expansion?
Although the series never specifically mentions it, anyone with cursed energy has the potential to use domain expansion. That is because domain expansion is an innate technique. It is more or less an extension of the innate cursed technique that a sorcerer or curse has. It also depends on individual talent and the ability to work hard enough to master such a difficult technique. However, there are exceptions such as Yuji Itadori and Maki Zenin. In the former's case, he is overflowing with cursed energy, even though it belongs to Sukuna.
Sukuna can use an innate domain while taking control of Yuji's body. However, because Yuji doesn't have an innate cursed technique of his own, he is unable to use domain expansion. Maki is bound by Heavenly Restriction, due to which she gained immense physical strength. However, the cost of having such strength was to be deprived of cursed energy. That is why, despite being a direct descendant of a legendary clan, Maki is unable to use a domain expansion. Even after Maki gains the ability to see cursed spirits in the manga, she possesses negligible cursed energy.
Do Domain Expansion and a Simple Domain Match Up?
The fundamental characteristics of a simple domain are not that different from a domain expansion. Simple domains were invented during the Heian Era for weaker sorcerers. Therefore, it makes perfect sense for someone like Miwa, who doesn't yet have the talent to achieve her own Domain Expansion, to be able to use a Simple Domain as one of her signature techniques. This technique allows the user to attack anyone who comes within the presence of their small barrier automatically and also protects the user at the same time.
Metaphorically speaking, a sorcerer wins a fight through Domain Expansion by overwhelming the opponent with their refined domain, the selfish manifestation of their presence and soul. Simple Domains -- and by extension Domain Amplification -- act as ways for their users to stand their ground by manifesting their own cursed technique in small quantities, enough to counteract their opponents' overwhelming force.
Does a Special Grade Require a Domain Expansion?
In actuality, a domain expansion is unquestionably required to achieve a special grade. Megumi's example suggests that just having the ability to use an innate domain does not automatically qualify one for special treatment.
However, the fact remains that not a single special-grade sorcerer is unable to use domain expansion in Jujutsu Kaisen. Special-grade sorcerers are considered to be extremely strong, therefore, it is only fair that they can use the ultimate technique before calling themselves 'special'.