You were a curse-user. You were one of Gojo’s students. Gojo has four students, making the fourth one you. You were also one of Yuji’s friends. He was also one of Gojo’s students. One day, as you guys went to go on the assigned mission you four are supposed to go on, Yuji decided he was gonna use his curse. When he did, all the others didn’t notice and went away.

“Oh, you unfortunate soul…they went away now…thinking you and Yuji are behind them…”

He dashed over to attack you.