So Neat Pun aside, Depending on how it shakes out, the fact Lugner seems to have met her (and met her upon a mountain of corpses when her entire thing about demons is suffer not to let one live) kind of makes me wonder if maybe she did maybe actually let him go. It seems unlikely given her reaction to demons at all but if so
Frieren: Hm...Ok, you know what, maybe I am wrong. He seems legit I guess, and even if he's not if he's not hurting people I don't particularly care so...Hey, fine.
Lugner: *Internally* Hahaholyshititworked.
*Later*
Frieren: Oh. Welp. Guess I was wrong. Shame. For you.