I'm Fighting the Villain for His Character Setting

Hua Shanyuan Rin, a timid high school student at Ice Emperor Academy, is locked in a restroom during a school bullying incident and accidentally suffers a blow to the head, scrambling her memories. When she wakes up, all she has by her side is a diary-style fanfic from another world, The Villains' Diary Exchange. Hua Shanyuan Rin, with her muddled memories, reads the entire diary and pieces it together with her daily life. At last, she realizes the shocking truth: It turns out that the timid Hua Shanyuan Rin is just a disguise. Her true identity is the woman who seeks revenge on the world for her dead lover: Kibutsuji Naraku, stage name Tobi the Love Warrior, also known as Lord Aizen! Hua Shanyuan Rin: Back when I was still called Tobi, I once fell in love with a man who could never love me back. His name was Kikyo, a male "priestess" who wielded a bow and arrow. Though he was forever in love with Teacher Byakuya, known as the Golden Flash, I never minded being his devoted simp. That is, until he died protecting Konoha at the hands of my friend and eternal nemesis, Yoriichi... To avenge this heartless world that took both my lover and my friend from me, I decided, under the guidance of the reliable senior Madara, to become a Love Warrior. Taking the name Kibutsuji, I will lead the Arrancar army back from hell and eventually stand above the heavens! Now, feel my pain, world! Tobi & Naraku & Aizen & Muzan: Shut up! #Ever since I got a mental illness, I've become more and more energetic# #For some reason, every time I finish my monologue, someone wants to hit me# #There's nothing and no one in this world I fear, because I am Kibutsuji, the Love Warrior!# *Silly comedy series / villain-tormenting series / making villains' blood pressure rise series *The heroine is ridiculously overpowered and a naive sweetheart, convinced her villain persona will never crumble Theme: Believe in yourself, and you can create miracles