Raze had already used a lot of mana, and Qi in his fight against Murkel. He was pushing himself, even taking Qi pills and mana pills during the fight. Only small amounts rather than the cursed pills.
It was painful for him to move, as he was forcing his body to go beyond what it could. Using the Ten Descending Steps in succession took a lot of Qi, and took a toll on his body. Honestly it was somewhat what Raze was relying on to finish the fight and yet it hadn't done so.
Thankfully with the Lux Sword and the blazer, he was in a better condition. It was helping his body heal from the down side of already having used a Cursed Qi pill and now using regular pills to supplement his mana and Qi.
Regardless of it all, he was now in the current situation, where the fight was still continuing on, and he was unable to finish off the opponent in front of him.