Quote Originally Posted by mfauli
I don't like how killing each other is allowed and those 3 killed by bird monsters didn't matter to Denken and his group
Yes to organisers are okay with killing.
No, it did matter to Denken.

As for Ferns capture, I assumed they got her because Fern is also a master of mana suppression. She's better than Frieren at that so she might not even produce mana when she moves, allowing her to place the bird in the cage.

We saw the examiner drinking tea in one of the shots and the bird just sits in the table, so they are approachable in a sense.