These modifiers make it possible for enemies to have different perks depending on the given week. The main advantage of this is that it would make expeditions less repetitive and more unpredictable. For example, the Eternal mutation gives enemies Void Resist II, making void-based damage a far weaker choice whilst active.
The new end game
The current design for Expedition Mutators is available to test out on the PTR test realm right now. All players who opt-in will get a set of starting 600 Gear Score equipment to take part. Equally, a generous amount of keys have been provided, making it easy to access and host as many expeditions as desired. Those wanting to provide feedback on the Mutators can do so on the official New World forum.