I don't know how doable this is, nor do I particularly dig the idea. Being alone in the wilderness at night without armour and being caught by 5 mobs already seems fine. Perhaps it could be a beacon trait, along with faster spawning? I don't know if that's like... reasonable, though. It seems like an okay idea though! I just don't really dig the idea of it being server-wide. Maybe for some specific mobs, but 100% across the board is a bit much.