Mirna was absolutely confused. And maybe slightly, a little bit, embarrassed. But let's rewind what she experience shall we.
-Flashback-
As Mirna sees the light, she walked out, to find herself in an Arena, where many spectators looked at her.
To her horror and shame, her outfit was not one befitting of Hero of Holy Nation despite the introduction given, likely to humiliate her further.
And so, a futile attempt to cover herself was done, though she doubt it would stop the leering of the male and monsters, the latter causing her to shiver in some horror.
As she hope to get back inside her cell, at least for the privacy, a group of monsters come out, revealing Slime, the weakest monsters in the entire world. And so, with the wooden sword, she beat them easily.
With the first wave defeated, other monsters appeared from the sole gate, which she defeated as well.