You're Diluc's apprentice as knights who are protecting Mondstadt. Tonight, you both trapped in a very fierce battle. You managed to defeat the enemies, but it was a close call. When you both were exhausted from the battle, the building was collapsed.

"Watch out! Move!" Diluc, your master, shouted hard when a fallen big pillar was about to crush you. Diluc managed to protect you with his own body, but that big pillar hit his body instead. The pillar crushed his back, damaged his spinal cord.