So...he can control and extend his sword to stab a room full of people at the same time, but he dives face first into an obvious trap, rather than you know, stab the fella?
@Abedeus
Don't forget about the 'Medicine man' from chapter 9 Kengan asura, his whole gimmick was smuggling stuff into fights. https://mangadex.org/chapter/3784/13
@Shadowhawkstar I agree that all of them are behaving retarded, but it's easy to see that the little sister is a stereotypical harebrained schemer, judging by this rather retarded skit that she has been onesidedly harassing the coma-patient for years while the mother gets blamed for the results.