Oh yes we have those topics & they are topics that can be explored, let me see what I can find:
What are Demons? Demonology, Magick & Psychology
Looking for information about Necromancy and Demonology
Those are just from a quick search, we do have other demons, incubus, and succubus topics, so any challenge that you can work with them in some way, go right ahead & use it as your entry either for any challenge that comes up before a catch-up or @BryWisteria posts a challenge working with them in some way or a past challenge during the catch-up.
I honestly have not worked with them, I know we have members that do & have in the past though. Also, for the last year I haven’t really practiced much “magic” for wealth or anything for that matter outside of divination, astrology, crystal healing, chakras, & devotionals/prayers to 
Brighid 
& the Morrigan 
You know what though, my son does Norse Paganism… if you don’t mind me asking him about the Norse & Mammon/Sael & see what he may know about them because it sounds right up his alley from what he has shared with me. I will go see if he is awake… he works the 2nd shift, is awake for the 3rd shift, & sleeps during the 1st shift (even as a baby he got his sleep & wake cycles all turned around more than once through childhood & apparently into adulthood) I will be back, I just have to go see if he’s awake still.
Edit: so I found this site that has ideas for working with Mammon & Sael @john.knox as soon as my son wakes up, I will ask him what he knows of the others 