That item is pretty OP. You could just spread it over an enemy while they're sleeping and in a few minutes the gradually fade out of existence. No evidence.
To be fair she was most likely going to end the relationship whether or not she met the sister. The only reason she even agreed to go out with him was because he confessed in public and she consented because of the pressure. His chances were doomed the moment he asked her out in public.
@greatninja3
She may be immortal but it does take time for her to regenerate. Plus as I said, the puppet may have resistances (most likely not). The point is that she likely already know if it is effective or not because she already checked their status. Actually hitting them is the hard part...
@greatninja3
They probably have a resistance against it. Even if they don't have a resistance, fact is that fighting them one-on-one is dangerous and two-on-one is suicidal so the only way out is to retreat.
@Siikalahna
The MC literally just came to the town a day ago and is finding out about stuff while being a criminal. Cut the MC some slack, he/she doesn't even know the full scope of what's going on and who is and isn't bad plus its not like he/she is some heroe of justice trying to save the...