Take a look at
7 Rabbit's background. (I've been flipping back and forth randomly on using the Aztec or Mayan names - I called the underworld Xibalba in that writeup, but I've been using Mictlan in play. Maybe we should be more persistent, where some of the Valley of Bone kingdoms are "Aztec" influenced and others are "Mayan"?)
I like your kingdom of liches idea - it could even be the same one Rabbit's from. I've already established in RP that Rabbit's been taught that the God of Death is a horrible, evil creature and that therefore becoming undead in order to stay out of his hands is a GOOD thing, so this fits your concept perfectly! (I set up some background for this in
the tavern - maybe I should copy that to the wiki.) On the other hand, I was picturing succesfully becoming undead as being more rare - one of Rabbit's ancestors is famous for it, and if EVERYONE becomes a lich at age 150, that wouldn't be very notable.
So maybe we should be from rival kingdoms, where yours knows the secret of an easy path to lichdom, and mine is always trying to steal it from you?
EDIT: also, I figure Rabbit is fairly famous where he's from, so you may have heard of him. As "that quack astronomer who's always ranting about something".
Another idea I had, which I hadn't really been able to work in, is that they're not called the "Golden Kingdoms" because of their mineral wealth like outsiders assume - they're called that because they were the first to cultivate
corn. (Of course, they're also highly wealthy, so the name has a double meaning now.)
EDIT again: I see you're a ritual caster. I've been RP'ing in the Echoes of O thread that ritual magic in this area works
completely differently than in the Valley of Bone. (Rabbit has never heard if residuum and is fascinated by the concept of it powering spells.) Rabbit's ritual casting was specifically astrological, so if you're from a different Valley of Bone mystic tradition, maybe yours still works and you've brought supply of whatever mystic items you need. (So people seeing you cast would find it strange and different to the versions they're used to.) Or maybe you've already learned the local ways of casting since you got here. Or, if you don't like the idea, maybe it's just Rabbit's kingdom's brand of magic that doesn't work, and he's just sheltered and doesn't know how the other kingdoms do things. Which would kind of tie into the idea that lichdom is common in your kingdom, and his hasn't figured it out yet - maybe he's from the sticks!