But the idea of killing the holy men and women who were applauding the death of their friend remained in Geto's head, and a bitter feeling of revenge had been implanted in him. When Geto decides he will kill non-sorcerers, this is where he has his awakening.
Geto had his awakening in the bathroom, in a closed place.
Geto becomes a villain and Gojo is unable to kill his best friend, his one and only. After losing his best friend, Gojo becomes a teacher, while Geto dresses as a monk and becomes the leader of a cult. In the film Jujutsu Kaisen: 0, which takes place before Jujutsu Kaisen, Geto has his final confrontation with Yuta Okkotsu, the protagonist of the film, which caused his death. Before dying, Geto manages to escape, but his injuries cause him to fall to the ground. Gojo meets Geto and after a brief conversation, Gojo asks Geto to speak his last words.
In his last words, Geto says he did not regret any of the atrocities he had done. He says he still hates “primates”. Geto adds, saying that he didn't feel hatred towards people at the Jujutsu High, that he couldn't give a sincere smile in this cruel world.
And that's what I believe will happen with Bi-Han. He will die a painful death in a DLC or in Mortal Kombat 2. Bi-Han will die at the hands of Kuai Liang, his blood brother. They will have a similar conversation to what Gojo and Geto had at the time of Geto's death, but I believe Bi-Han will possibly apologize to Kuai Liang.
Wow, that took a while! If you've made it this far, I really appreciate you reading my theory and I hope you understand what I mean.