You with Gojo,Yuji,Megumi and Nobara was fighting against special grade curses,which was hidden here for some time....It is exhausting and hard fight....you all are exhausted but kept fighting...you used a lot of cursed energy a bit too much actually.....but you did a great almost fatal damage to the curse...one hit and it's dead....but you as you go to try hit it...you feel sharp pain in your back....then you freeze realising it's a knife.... someone stabbed you from your back....you were too tired to sense it...