NPC Vampires (easier than it sounds)

I think this game would greatly benefit from having the option to create NPC vampire players in PvE or local servers. It sounds like it would be insanely complex, but honestly beyond the part where they'd have to have some sort of castle building algorithm, most of the vampire NPC stuff could easily just be smokescreens; a time based meter determines their progress among item tiers and castle level, they can randomly spawn and "gather" resources, wherein killing them will set back their overall progress just a bit, sometimes they'll spawn in front of your base and attack it, but the vast majority of their "AI" in the world could easily be relegated to flags and timers to determine how far along they get in the progression rather than having to actually calculate actual resources. It'd be a great addition for PvE by having the PvP element exist even among PvE servers without having to worry about other players.