After the battle with Leon, Dan simply stood there unmoving. The truth was after using TRANSCEND Dan's consciousness was already flickering on and off. When he was hit in the back by Leon's scythe Dan was already unconscious then, and his body simply moved on its own. He was able to kill Leon this way as he sustained multiple injuries.
A few minutes after Leon's death, Dan was jolted awake as an indescribable pain assaulted him. Blood flowed out of his body like a river. If it was any other person, even someone at Richter's level had so much blood come out of him, he would already have fainted and might've died, but it was different for Dan. Aside from Rika who was biologically better than all of humanity, the endurance of Dan's body was only second to her.
