[@Arawak] The library being built in the mountains somewhere doesn't really interfere with the planets history. If he arrived before Vaulthuz rose he likely would have never heard of the place so it would be in little danger, save for the occasional wandering undead. If he arrived afterwards Vaulthuz spent most kf his time underground trying to create a portal so odds are he would never make contact. The only thing you could include if you like is some minor skirmishes with some undead but its hardly a priority. 

Oh and as for how our characters do make contact, perhaps Kitamin tries to explore the area when he awakens and finds the cave Vaulthuz had placed the portal to Ecetopia in. Then they meet, a brief discussion and your character decides to join Vaulthuz. Unless you have other ideas in which case go nuts.