Realistically speaking, it's only a matter of time before some human demon hunters try to kill her. If the demon hunters are simply paid to bring in proof of killing a demon, she's as good as any for those of low morals. In the business of killing, those of low morals aren't so scarce. Even if the first ones didn't manage to bring her down, she would, nonetheless, be accused of having wounded/killed human demon hunters. In other words, she would be labelled as an evil demon just like any other demon.
Well, this is a oneshot, so we don't need to witness that inevitability.