Scentless Hunger Worm

At the center of Ciera's sole, a red, swelling piece of meat could be seen. At the center of the swollen part, was a small black dot. 

Seeing that swollen part, Yakob's face went pale, as that swollen part only implies the truthfulness of what Ban had just said. 

Not wasting any time, Yakob drew out his sword and prepared to slice away the swelling part, in a bid to get rid of it and possibly the worm that had caused it. 

"Don't. Slicing that away won't help. But if you want to injure her, then feel free to do so."

However, Yakob stopped on the spot when he heard what Ban said next. 

Seeing Yakob stopped, Ban continued. "From the size of that swollen part, I guessed that the worm had started drilling for more than twelve hours. At this point of time, the worm would no longer be on her sole, and instead, already travelled all the way up to her stomach."