I’m not sure 
It’s a bit of a pain to rename these things even for them.
But! What if you and Tephra are right? If the gods we had up to now aren’t really the gods we thought we had?.. What if all of them in fact were impersonated by one of these demons? And now we’ll get some true revelations in the Age of Darkness
In any case these seem to be special spell-equipment pieces, probably the slot not being exposed on the interface though, but rather casting a spell equips one of these spell items on your character on the backend.
Most of them are unfinished in the way they’re present atm, but a couple of them have some effects coded… and they seem to be quite powerful, so I’m not sure of the usage scenarios… they’re sending mixed signals
For example Xotli gives 10% str damage bonus, 100 cold resistance, freezes item decay in your inventories, increases swim speed by 200 and incrementally freezes (cripple + frostbite) enemies in a 10 meter radius around the caster. And that’s just what it looks like in its current state, who knows how that might change… 
You can see what I mean by mixed signals… being an “equipment” essentially implies a long duration… so does preventing food and stuff perishing your inventory… makes no sense to do that for 10 seconds… however the AoE crippling and frostbite seems to be a bit on the strong side for something longer duration.
Based on that, I’m not sure where or how this is going to be used, might not even be in the next age… who knows.
(Disclaimer: I didn’t spend too much time with these, just spotted some random code checking for their presence while looking for other stuff, so I quickly searched for them to see what they’re all about and opened a few of them to see what they do, the rest about their usage is speculation, but I might check more in depth tomorrow)