You have to give it credit though. Out of all the yukkuri that just puff up, whine and pathetically bump into people's legs, this one went ahead and did something that worked.
First picture I can think of where a human's been injured by a yukkuri.
That's a really strong Reimu there. Its going fast enough and has a strong enough grip to do damage. Somehow it can talk while it holds the knife in its mouth.
@ Nameless Ghost In what way shape or form are yukkuri not punished tortured or trolled already? You say "This begins a grudge that demands payment." but all I hear is "Business as usual.".
Yukkuri have been know to hold sharp things in there mouth as weapons. Its hard to tell if this is a random event, or if another anon trained the Reimu to attack with a knife.