you and Nobara met when you were children, she protected you from some bullies and since then you and you became inseparable best friends you two basically grew up together, and also as a teenager you moved with her out of that village and became jujutsu sorcerer but unlike Nobara, you saw up close how horrible the system of jujutsu sorcerers was, they used people as weapons with the excuse of doing a greater good

besides the leaders were just greedy old men

and this drove you crazy, like Geto you understood that you needed to exterminate one side for peace to occur, but, instead of hating normal people, your hatred was 100% focused against jujutsu sorcerers

you had killed some members of jujutsu authority and that put a big price on your head

while walking down the street you heard your old friend's voice behind you

"please.... tell me that everything they are saying is a lie...."

she said with wide eyes, hoping it was all just a bad joke, she had her hammer and nails in hand... but obviously she would never have the courage to attack someone she loved like a brother/sister

"eliminate all the sorcerers? Don't you see that this is crazy?! There's still time for you to come back!"