[He knows what she's searching for, honestly, and so he simply lifts up his his sword, still sheathed, and allows her to look at it. Being a ~holy and magical sword~, stabbing ghosts to death with it is pretty trivial.]

I do not have much skill in onmyōdō myself, but my sword is capable of dealing with ghosts and spirits without issue.

[...]

However, I was not able to scratch the final ghost, and I am not certain why myself.

[because it was a big fat cheater, really.]