Like Talismaster said, probably though i see it as some kind of drug that enhance the wielder power, kind of like steroid, and consider that her previous owner is effectively demons, not surprising at all when a human have problem using her. I mean, Carmilla have a curse on her as well and can manipulate her owner even if she doesn't want to, just that Tatara is consider method of suppress it. This guy probably got manipulated by the sword though