This flying castle is utterly wasted on this doormat, gullible idiot protagonist.
He (elf guy) has shown zero proofs to backup his story. Could be a total trap to lure in this idiot MC. Also, he had NO REASON, to accept that duel. I'm starting to think this protagonist has suffered from a brain damage.
Also, isn't the whole point of that slave seal that they can't betray their master..? By the looks of that bitch's smile, the elf guys story might've been total BS.
Yeah, great idea to take in enemy spies to our base, who are on constant war w/ other nations, and who are basically experienced murderers. Also a great idea to believe their story, and lower your guard at that moment.
I bet this doormat MC will give them a full tour of the castle on the next chapter, and show all the secrets to the enemy spies.