You'd think after so many near-death incidents Kumo would be a bit wiser. This attack with extreme arrogance was so stupid it's hard to believe. She has even used traps and ambushes herself, but suddenly she can't fathom others could do it as well? She had to be a bottom of the barrel student back in Japan. I'd have forgiven this if she had been at least a bit more thoughtful, even if it had still led to the same outcome, but at least she would have tried.