Why would i edit player indices? Where did i say npcs in realms exist anywhere else?
Realm container -> get x type of realms
-> update each x
-> Update entities in realm x
How is it hard? I mean i don't get how you get that my intentions changed?
Realm has container of areas, areas contain chunks.
Updater takes the realms, updates each player in each realm. Updates npcs in each realm, And updates other entities. Spawns required. And tbh, i haven't yet even thought about the processor, since i have no use for it yet, i have no intentions of doing it as of yet. So for now i'm going to update the "realms" in the main update system.
Unique npc indices as, Realm-specific npcs would have realm-specific ids, and they'd be inexistent on other realms. Transfering each type of entity is no necessity, but for certain things it would be useful. Also realm-specific death methods for players would exist, as in runescape also.
Realm is the nearest to it. Instanced world could be better, but i wouldn't consider the main world an "instanced map" as it by means, is static. Idk.