|Affiliation||Gilded Cage Guild|
Number 1 is a red devil and a low-level drug dealer under the protection of the Gilded Cage. Presumably, "Number 1" is a use-name, concealing their longer true name.
He is (untypically for red devils) a weak and cowardly creature. It has been explained that he is so-called demi-imp: A red devil that has gone for so long without making new pacts that he has been greatly reduced in stature and standing.