Okay, looks like we have a nice 2nd group shaping up. Still working on TheLaughingOne's character. Sorry it didn't work out AndyZ.
Nathan - Inheritor background is fine, and it can be a tattoo. Probably some strange arcane writings, unless you had a different idea?
Varian - So your character worked for the Zrillie, but was never actually a member? That's cool, he's probably have a token of service then, a silver amulet or bracelet. Presenting it will give you advantage on persuasion checks vs. Zrillie.
Claudia - The lore on the Vornstein works. There's about 100 noble families in Lupravia, the four I mentioned are just the major ones, so a 5th one that was once great but has since crumbled is fine.
Snake's warlock is finished I think?