Rare Crystal Sets are an exceptionally helpful item you can make in Once Human. They’re not going to be used for creating unique builds or providing defenses for your bases, but they’re a good way to build up a large amount of currency to purchase other items.

The primary currency you’ll want to have a lot of in Once Human is Energy Links. You earn it by completing nearly any activity you play, or many of the chests you open have a chance to reward you with a good amount of this resource. You use it to buy anything you may lack or don’t want to grind. Rare Crystal Sets are a solid way to earn a lot of Energy Links quickly, but not everyone can create them.