Blazblue: Phase Shift 4 Chapter 3

"I'm sure I've said this to all of you individually at some point already, but let me say it again: the Nox Nyctores are far more powerful than they look on the surface. They're all purpose-built for just one thing, and that's defeating the Black Beast. Taking the Black Beast down is the whole reason that these weapons exist. If they're wielded in battle against the Black Beast, they'll manifest extraordinary power, but in exchange for all that power, they'll take an appropriately large toll as well."

"What do you mean, they'll take a toll?"

Jubei cut in to ask her what she meant by that ominous phrase.

Nine's eyes got even more serious and she nodded her head before answering.

"Simply put, it's stress. These things constantly want their wielders to bring out more and more of their power. Their demands put mental pressure on the wielder, which manifests as stress, and the sensations and emotions that arise from that stress serve to further hone the weapons."

"So, their ability to kick ass depends on the mental condition of their wielder?"

"That's right."

If a Nox Nyctores' wielder could effectively control their weapon's influence on their mind, there'd be no limit to how strong the weapon could become. On the flip side, if the wielder were to be overcome by the weapon's influence, they wouldn't be able to preserve their own personality anymore and would eventually break down.