Fuyu: "I got a super dangerous demon sealed inside me so if I get killed/eaten, it'll be really bad. Thus, I must get strong enough to kill the demons first!
Good idea Fuyu. When you're in danger of being killed, the best solution is to become strong enough that you kill things before they killed you!
Nine clans: We must kill you because you cant protect yourself.
Fuyu: I have to be killed because I’m weak?
Nine clans: Yes.
Fuyu: Then I’ll become strong!
Nine clans:…have we made a mistake?
"(...) she's not different from a normal human."
A normal human wouldn't split a tree stump in half like she did even before she got possessed (chapter 1).