Dracula Endgame: The second chapter.
1. To access the endgame, there should be a gateway / portal that can only be accessed on a high mountain top, that requires bat form to reach. Keep in mind that no resources can be taken with you apart from consumables and blood-bound items (that can be devoured back into key resources)
2. The endgame zone should be procedurally generated, with a seed value. This means you can keep your existing world in the current game, but make the "second chapter" completely unknown.
3. Monster and Holy factions in the "second chapter" should be different, and not repeated, bosses too (obviously) --
(b) Igor (his infamous servant!)
(c) Vampires that roam (like the vampire hunters) that mimic PvP
(d) and some very OP new vampire hunters that will kill everything and anything in this zone.
(e) Werewolves as a big threat.
and enemies will attack your castles!
4. Save prisoners, and they will temporarily join your party until you leave a defined zone area (or die).