Jujutsu Kaisen 2 (jjk x oc)

Kuina Gojo is the 15 year old younger sister of the number one jujutsu sorcerer, Satoru Gojo. When her older brother was born, something shifted in the universe, blessing him with the six eyes and limitless techniques. But when Kuina was born, nothing happened. She was just added to the numbers of the Gojo clan and she started her training.

Growing up, Kuina found out she had weak cursed energy and she didn't have a technique she could apply her cursed energy too. So she was just a battery full of energy, waiting to be used. Kuina soon found out what her legacy would be. Kuina could give people her cursed energy, but people could not give her their's.

As the people around her grew stronger, she grew weaker. Kuina ended up despising strong people and wanted to live out a mundane life, hiding the fact that she could practice jujutsu. But after she ran away from the Gojo clan and her older brother Satoru found her, he forced her to attend Jujutsu Tokyo Tech High School, the school where he was a teacher.

Kuina grew to hate Satoru for his strength and ended up acting like she didn't know him. Kuina told everyone in the school that they were distant relatives, that's all. When Suguru Geto, Satoru Gojo's friend attacked the jujutsu sorcerers, Kuina was nearly killed by Geto after she revealed to him that intended to live out a mundane life to which Geto despised.

It's now Kuina's turn to enrol at Jujutsu Tech as a first year student. Being at the top of her class in terms of physical and mental strength and technique with different weapons, Kuina and her friend/someone she sees as a brother Megumi have been instructed by Gojo to collect all of Ryomen Sukuna's fingers.

But after a run in with Sukuna, Kuina takes it upon herself to break into Sukuna's abandoned shrine and awaken his younger brother Xavier, another special grade spirit who takes a liking to her straight away.