This article has manga spoilers! Read ahead at your own discretion!
From a shaman to the leader of curses, Geto has been focused on a future different from the Jujutsu community. His ideologies are strikingly erratic, and his means are meticulously planned. He is also extraordinarily thorough with the inside outs of the Jujutsu Tech schools and the reactions of the people concerned.
But Geto’s ideologies aren’t entirely his own, at least in the current timeline, as he was revealed to be an impostor being controlled by a weird brain, whose name was finally revealed in chapter 145. So, just what is this brain after? What is the future he is working so hard for?
Geto’s or Brain’s Goal:
Kenjaku, as Tengen calls him, envisions ‘the world to come’. But rather than creating a world free of curses, the brain’s goal is to challenge himself and humanity to evolve. And for this to happen, humanity has to face a grave disaster: fight or die against powerful ancient curses.
It is of note that the original Geto and Kenjaku have motives that are completely different. Both of them want to eliminate the non-shamans (basically people who cannot optimize cursed energy) but their underlying ideologies and reasons are strikingly different.

Geto had strong disgust for humans and even called them “monkeys”. Their weaknesses forced strong shamans to die in their stead. However, Kenjaku does not have this particular hatred for “weak humans”. The point of the Brain’s focus is this “weakness” in humans.
The fixation on evolving:
Kenjaku had always thought humans would achieve something unique. He wanted to unearth this real potential. This was probably why he experimented on humans and created the cursed womb while in possession of Noritoshi Kamo (old guy). Despite this, he was always held back by the limitations of the human body.

This forced Kenjaku/brain to rethink his strategy. Eventually, he came to the conclusion of making the human race evolve as a whole and breaking the glass ceiling which limited their potential. Cursed spirits are the necessary evil equivalent to the dire situations in the past for human evolution.
The future of the world & humans lies in optimizing cursed energy so that humans do not rely on shamans. Or rather, everyone is a shaman. This craze for evolution seems to stem from his repeated failures to go beyond the limits of human potential.
Thus, this idea also falls into place with his almost happy exchange with Mei Mei regarding this age’s shamans being powerful. He is enthralled to know that there is potential in the new generation to grow, unlike his failed experiments.

How does Brain/Kenjaku plan to achieve his goal?
Fundamentally, Kenjaku wants to employ the survival of the fittest methodology. Or that’s what we thought initially.
We assumed that in the culling game, with the special grade curses and curse hosts running rampant, there will be only the options of “do or die.” Humans will be forced to master the use of cursed energy. This move will create a world where only the strongest and the ones who can evolve could survive.
However, his plan seems to be totally different come chapter 145. The culling game will only serve as a ritual, using which the human beings of this country would be sent to the other side.
Merging humanity with Tengen:
According to Tengen, Kenjaku is aiming to evolve humanity (in Japan) by merging them with Tengen.

Ideally, Tengen should only be able to merge with the Star Plasma Vessel. However, since Toji foiled the assimilation 11 years ago, Tengen has constantly evolved to the point where they are no longer a human. They are much closer to a cursed spirit, which makes him an easy target of Geto’s cursed spirit manipulation.
Kenjaku wants to merge all of humanity with Tengen. By doing so, these humans will evolve into something more than a Jujutsu Sorcerer. They will become all-knowing entities similar to Tengen. But they won’t have a physical existence or self-awareness like Tengen does.
Tengen is only able to maintain their form and awareness thanks to their barrier. However, humans won’t be capable of doing so. And even if one person rages, it will cause large scale destruction throughout the world. Knowing the downside, Tengen does not want to merge with the humans or go along with Kenjaku/brain/Geto’s plan.
However, since they are a potential target for cursed spirit manipulation, Geto can consume Tengen and make them act according to his own will.
This is not the first time brain/Kenjaku has attempted to carry out his plan. He has been planning this for hundreds, if not thousands of years. However, everytime he got close to Tengen to prevent his assimilation, a six eyes user stopped him.
Connected by fate:
In chapter 145, Tengen says that the Star Plasma Vessel, Six Eyes user and Tengen are connected by fate. Everytime an assimilation is about to take place, a six eyes user appears to protect them. Kenjaku was defeated by a six eyes user the first time he attempted to work out his plan.
The second time, Kenjaku killed the six eyes user and the star plasma vessel when they were one month old. However, during the time of the assimilation, a new vessel and a six eyes user appeared, foiling Kenjaku’s plan for the second time.
He then concocted a plan to seal the six eyes user. If they are sealed, they won’t be able to interfere with Kenjaku’s plan. And at a time, only one six eyes user can exist. This is why he began the search for the prison realm. While Kenjaku was still looking for ways to make that happen, fate somehow helped him out.
11 years ago when the merger was supposed to happen, Toji Zenin interfered and killed the Star Plasma Vessel. A new vessel was not found and Tengen began to evolve. This was the perfect premise for Kenjaku. Later, he also chanced upon the body of Geto Suguru, who could use Cursed Spirit manipulation, which could be used to control Tengen in case they refused to be a part of Kenjaku’s plan. Six years ago, the prison realm also fell into his hands.
Kenjaku/brain carefully planned his steps up to the Shibuya Incident to make full use of the Special Grade curses. His plan was a two-pronged strategy: seal Gojo Satoru in the Prison Realm, and earn the favor of Sukuna. He also made sure to be an invisible hand directing the curses to do the dirty work for him.

The devastation that will begin now will lead to mass deaths and significant global implications of cursed energy.
What are your thoughts on Kenjaku/brain’s plans? Are they morally gray? Let us know your opinions in the comments section!
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