The strongest sorcerer in Jujutsu Kaisen is Satoru Gojo.
What makes Gojo the strongest is his Six Eyes.
In this article, a native Japanese author explained the Six Eyes taking the Japanese backgrounds into consideration.
Abilities of Six Eyes
Let’s start with the abilities of Six Eyes.
Seeing Cursed Energy like a Thermography
As described in official fanbook, Six Eyes can see cursed energy very clearly.
However covered by sunglasses or blindfolds, Six Eyes can see everything like a high-resolution thermography.
On the contrary, if Six Eyes were not covered with sunglasses or blindfolds, too much information would overload the brain.
This is the reason why Gojo always wears sunglasses or blindfolds.
By the way, Gojo’s sunglasses are almost pitch black, and ordinary people can’t see anything through it.
Also, Six Eyes can perceive the objects that have no cursed energy by seeing the flow of cursed energy and its residual parts.
Seeing through Cursed Techiques
The Six Eyes can see cursed energy like a high-resolution thermography, so in some cases it is possible to see through the effects of cursed techniques.
In Jujutsu Kaisen Vol. 8, Gojo’s Six Eyes saw through the cursed technique creating 5 clones and moving the main body among them.
In this example, Six Eyes discerned the difference between the cursed energies of the alter ego and the main body.
However, since the Six Eyes’ ability is to see cursed energy in detail, it is not possible to fully know the effects of all cursed techniques.
For example, even Six Eyes would not be able to see through the complex cursed techniques such as Higuruma’s and Hakari’s techniques.
Precise Manipulation of Cursed Energy
Sorcerers who have Six Eyes can manipulate cursed energy precisely.
This precise manipulation is necessary to control Limitless cursed tecnique.
In other words, the Limitless cursed tecnique cannot activate without Six Eyes.
Even Toji Fushiguro considered Gojo Satoru dangerous because the combination of Limitless cursed technique and the Six Eyes is a one-of-a-kind talent in hundreds of years.
No Loss of Cursed Energy
Satoru Gojo, a sorcerer with the Six Eyes, can activate Jujutsu with no loss of cursed energy.
Actually, in Jujutsu Kaisen Vol. 17, Okkotsu said “But sensei (= Gojo) has the Six Eyes, so he loses almost no energy when he activates a cursed technique”.
Perhaps, by observing the loss of energy with the Six Eyes, the activation energy of cursed technique would be reduced.
In addition, Okkotsu also said “After all, I can run out of cursed energy, but he (= Gojo) doesn’t”.
The reason why Gojo doesn’t run out his cursed energy would be because the Six Eyes can minimize the loss of cursed energy and the amount of consumed energy is less than the amount of natural recovery.
What a cheating ability using the powerful Limitless cursed techniques and reverse cursed technique without worrying about running out the cursed energy .
Japanese Meanings of Six Eyes (六眼)
The Japanese meanings of Six Eyes (六眼; Rikugan) are explained here.
六 (Riku)
“六” means “Six”
眼 (Gan)
“眼” means “Eyes”
The pronouce of “Riku” is very rare in modern Japanese.
Normally, “六” pronounces “Roku”.
The pronounce of “Riku” is related with that of old times.
That is because the motif of Six Eyes is a word of Buddhism.
Motif of Six Eyes
The word of “六眼” does not exist in our world.
The motif of Six Eyes would be “Abhijñā (六神通)”
Abhijñā is a word of Buddhism and represents the six types of superhuman abilities that Buddhas and Bodhisattvas possess.
Abhijñā（wikipedia）
1: “Higher powers” (iddhi-vidhā), such as walking on water and through walls;
2: “Divine ear” (dibba-sota), that is, clairaudience;
3: “Mind-penetrating knowledge” (ceto-pariya-ñāṇa), that is, telepathy;
4: “Remember one’s former abodes” (pubbe-nivāsanussati), causal memory, that is, recalling one’s own past lives;
5: “Divine eye” (dibba-cakkhu), that is, knowing others’ karmic destinations; and,
6: “Extinction of mental intoxicants” (āsavakkhaya), upon which arahantship follows.
As described above, the Abhijñā seeing through everything is corresponding to the ability of the Six Eyes.
Therefore, Six Eyes of Jujutsu Kaisen would be based on the word of Buddhism, Abhijñā.
Six Eyes, Tengen, and Star Plasma Vessel
The Six Eyes, Tengen, and Star Plasma Vessel are all connected by fate, as Tengen said in Jujutsu Kaisen Vol. 17.
Tengen also said that although Kenjaku killed Star Plasma Vessel and Six Eyes less than one month after they were born, Six Eyes and Star Plasma Vessel appeared on the day of merging.
So, Six Eyes, Tengen, and Star Plasma Vessel are strongly connected by fate, and no matter how many tactics Kenjaku tried, he could not prevent the merging of Tengen and Star Plasma Vessel.
However, this connection have been destroyed by Toji Fushiguro who had escaped fate trough the power of heavenly restriction.
As a resorult, Tengen failed to merge with Star Plasma Vessel.
However, even Toji was not enough to erase the Six Eyes Gojo, and Kenjaku plotted to seal Gojo.
The reason for sealing Gojo instead of killing him is because two bearers of Six Eyes cannot exist at the same time.
In addition, Kenjaku describes Gojo as “too strong”, so it would be one of the reasons for sealing him that it is difficult to kill Gojo.
The above is the relationship between Six Eyes, Tengen, and Star Plasma Vessel.
Possibility of Losing Six Eyes
There is a rumor, on the Internet, that Gojo would lose his Six Eyes.
The basis for this rumor is the OP of the anime Jujutsu Kaisen.
The OP of the anime Jujutsu Kaisen contains various foreshadowings about what happens later.
Here are some examples:
The left half of Nanami’s body is in shadow, which would suggest that Jogo will burn the Nanami’s left half in Shibuya Incident.
The composition of Gojo walking with flowers matches the composition after killing the transfigured humans in Shibuya Incident.
The shadow cast only on Mekamaru would imply that the traitor was Mechamaru.
The mysterious fish that appears in the OP is a dead migratory fish called Emperor Angelfish.
The dead migratory fish, “死滅回游魚” in Japanese, would imply the Culling Game, “死滅回游” in Japanese.
The scene where Pseudo-Geto pours black honey on vanilla ice cream would imply the curtain used in the Shibuya Incident.
As mentioned above, the OP of the anime Jujutsu Kaisen is considered to be a foreshadowing of various events that will occur later.
And in this OP, Gojo’s left eye was depicted as if it loses the light as shown below.
Furthermore, in the OP of the app version of Jujutsu Kaisen, there is a cut-in where Gojo’s left eye cracks.
And the lyrics that flow in each scene are as follows.
Anime Jujutsu Kaisen OP
・Japanese：もう戻らない、金輪際後悔はしない
・English： I won’t go back anymore, I won’t regret it forever
App version OP
・Japanese：この身が焼けても守るものを知って
・English：Knowing what to protect even if this body burns
Perhaps these lyrics imply that Satoru Gojo will sacrifice himself to protect his students…
These are about the possibility of Gojo’s losing Six Eyes.
Postscript
This is the article about “Six Eyes Eeplained by a Native Japanese”.
Other articles explained the interesting and important issues in Jujutsu Kaisen.
Plese read them as well.
In addition, the Japanese version of this article is here.