I Cosplayed the Sun-Breathing Swordsman and Became the Cult Leader's Younger Brother

It's a little complicated... I cosplayed as the strongest Sun Breathing user, carrying the leader's [Bandit's Secret], and rescued a child who was hit by a car. Then I was reborn into the world of Jujutsu Kaisen, and didn't regain my memories of my past life until I was fifteen. All right, all right, I said it was a little complicated. Anyway, by the time I recovered my memories of my past life, my dear older brother was already seventeen. His defection was just around the corner. Me: ... Damn it, let's just destroy everything! *Pairing: the leader *The protagonist is neither a Sun Breathing user nor the leader, so don't view him through that lens. *Since someone brought it up, here's a quick content warning: OOC, personal headcanons, fanon, and major changes are present. [Hope you enjoy reading, darlings (wink~)] Coming soon The next story will most likely be The Primordial Mother Turned Out to Be Me The moment I put on those heavy horns, I transmigrated. The moment the stars and souls merged, I [understood] everything. I am Tiamat, but only as a concept. I am not Her, only a shadow imbued with a projection of Her power. That supreme creator goddess gave birth to all life, yet at the birth of the new world, she was abandoned by the children she loved and cast out by the world. She sleeps in imaginary space, and her powerful obsession became my wish. A God's Eye is a god's gaze cast upon the world. A powerful wish will draw the gods' attention. One day, a mad whisper drowned out the thoughts of everyone else, and the gods heard a sorrowful woman's voice: Don't leave me... Don't go... Please... don't love me anymore. Theme: Forge ahead no matter the odds, and light will follow the darkness