Dark Matters are good at 'brainwashing'.

The list of the abnormalities:
Army in Pink
Melting Love
Old Faith and Promise
We Can Change Anything

"여기 세 잔의 찻잔이 있네요. 여기는 세차장입니다."
This is the original version of the pun over there.

세차장 means car wash, but in this, 세차장 means '세' 잔의 '차'가 있는 '장'소. (a place with three cups of tea)

Dark Matter Blade: I don't drink tea to fight, I drink it because it's delicious.

Another crossover! Haha!
They are the librarians from the Floor of Virtue. The designated librarian is 0.

Dark Matters have to work for survive in the city.

They questioned to 0².
"Are you Watching Us, Your Grace?"

Mild-ish LoR spoilers