there's a moment you get to choose a new decoration for the hotels lobby if you have arts background. choose one of the 2 artifacts to select who the new guest is. the other artifact that's from the already present guest can be gotten in the valley.
Viewing post in About Chapter 16, I have to if I recruit additional employees?
your character must have arts background. Khembish, Themba and Wolf each have an artifact tied to them. Normally, you can find the artifact of the one you first invited in the valley, and that will increase their stats.
In the arts background, you can select one of the other 2's artifacts to decorate the lobby, the artifact you choose will bring in that new guest.