After completing an endgame expedition once, players will receive a codex and orb that allow them to reply that expedition with a mutator active: These increase the challenge and rewards, modify both normal and named enemies, up the complexity and unpredictability of enemy encounters.
The exact combination of expeditions and mutations will rotate each week, and players battle their way up through increasingly difficult challenges (there are 10 difficulty levels on each expedition mutator). The mutations will also have a base difficulty for all players, but then scale individually for each player based on their gear score.
The below developer video shows a team of four going through an expedition with mutators active, showcasing some of the new and fiercer enemy mobs.
As New World is an MMO, there's a whole bunch of faff around crafting the orbs and minor changes around their inclusion, all detailed in the patch notes: More generally, they come alongside a re-balancing of expedition drop rates and rewards, and named enemies in particular should be much more lucrative.
The patch also adds umbral shards, which make me think of Bayonetta, but here are a new resource that will let players take gear from level 590 to level 625: Acquiring these shards is part of the rewards for the mutated expeditions.
All players will be happy to hear that the patch dramatically reduces the cost of fast travel, and has added six more 'spirit shrines' (which is where players can travel to).
New World seems to have settled into a nice groove, fishing bots aside, and Amazon Game Studios has been more transparent than we might have expected about the mistakes it made over the launch period. Who knows: An improved endgame might even be enough to tempt Fraser back.