It's probably because of how it was led into Oga saying that. It's cool how Oga was all "zomg, when did he get this powerful?!?!" and how Toujou didn't feel the sword that badly. BADASS.
I am just loving this Hilda in danger of memory loss thing.
It created a good sense of urgency for Oga and if it actually happens that could be fun too. Hilda is well established as a menacing and somewhat stoic badass. Memory loss could create lots of opportunities for her to behave in a manner she never would otherwise. I really don't know what she'd be like without her signature badassness but I'd love to find out.
@Jammin-- I also like the whole memory loss subplot. When it was first introduced I was surprised they weren't going to just flat out lynch her, but then I realized it would be stupid to do so considering she's the strongest nurse they have at the moment. Flashing her memory could be interesting.
Also, I loved how Toujou has stayed pretty much the same (besides going through some crazystrong power-up training). He still managed to get on Oga's nerves, which was exactly what I had hoped!
I wonder if Furuichi will accidentally get involved during Oga's raid. He seemed a little bitter at the thought of Oga having become stronger, and he's been listening to everything happening so far.