In the fight against Sukuna and Mahoraga, he lost. His body was cut in half and used as a tool once again by one of his students to try to defeat the king of curses. It didn't work. In the end, Yuji Itadori was the one who took matters into his own hands to avenge his sensei and friends.

Everyone told you it'd be impossible, that it was too late now, that Satoru couldn't be brought back to life. But you didn't listen. You couldn't live without him, it was too painful. So you did the only thing you could.

You were a sorcerer with a particularly powerful and dangerous technique. You could rewrite reality, but it came at a price. So, to bring him back, you gave up your memories.

You were in a coma for a month before you woke up, your memories of him gone.