Chances are that it was an A- or even an A rank monster. A monster of that class, other than the knights, no one can handle it.
"I see," Grey nodded. He then looked at Delicia questioningly, "If I may ask, how do you know the exact makeup of the monsters inside the jungle?"
At that question, the latter gave him a self depreciating smile and explained, "It's because I have been trying to clear them by myself for the past few months. The previous lord of the city asked for a fee of 300 gold coins. There is no way a poor village like us can collect such an amount even if we sell all of our possessions"...
"Since there was no way to ask for the help of the knights, I took up my sword again after many years. However, the result is as you can see…"
Indeed, had she been powerful enough to clear the monsters, the village chief wouldn't have had to come to their city with the request again. That said, for a former knight to be in such a state, her injuries might be quite grave.
