Even though this is Korean and they like to make cinnamon bun 2ND leads like it's a mission from God... Let's just hypothetically say this guy is her friend.
If I knew my friend got sold off to pay their parents debts to a ***literal monster*** and I had some talent with the sword, you bet I'd go off and try to free my friend. Or, if that sword is any indication, give my friends the weapons needed to protect themselves.
Maybe he'll be lame later, but right now he's acting like a real friend. So far he's acting like a stand-up guy and I feel sorry for such a decent character getting roasted.