A first person scrolls like MMO sandbox, but each server has it's own lasting history. Like, instead of making all the legendary items, players doing fantastic things will get a prompt to turn part of their equipment into a legendary item. They can add a relevant modifier, request a unique name, and from that point on the item works by legend rules. It can't leave that server, if you die with it the item disappears and becomes a reward for a dungeon. The item tracks people who have owned it so you can literally see the history.

It could have player ran factions. Not the, "everyone makes their clan of 1" like most games, you'd have to take x players or be an affiliate of a larger group. Then you could have a schism in the mages guild when a bunch of affiliated players break off due to a player made rule, or the revival of a dead guild as former players return and begin recruiting again.

All the while, the servers each run entirely independently with unique history. You could move between them as the same character if you leave your legendary items behind so you can participate in player made events or when trade goods between them, but Excaliber on server A literally doesn't exist in server B, and the kingdom of guy1 doesn't have the same standing here as it does there.