When coming to the island, although Raze knew his magic wouldn't work, he had still brought one of his most important items with him—the cursed Qi pill. The pill would restore all of his mana, but the downside was that after a minute, all of that mana would disappear.
In many situations, he had used these pills to help him out, but on an island where he was unable to use mana anyway, what was the point? However, Raze knew that the pill also worked on Qi, so if placed in a tricky situation, he had brought them anyway, unsure whether the Qi pills would work or not.
In the end, he had decided it wasn't even worth him trying to use it against Mosak. Having his Qi back wouldn't help him because none of the techniques he had used so far had worked. The issue was, all of Raze's Qi was at an all-time low.