It continues to vex me that 'Where in the world is Carmen Sandiego?' doesn't properly scan if you replace 'Carmen Sandiego' with 'Xur' (if you have any ideas on how to make it work, please let me know), but ah well. Destiny 2's merchant with the most is back this weekend, and this time he's hiding out on Io.
To find him head to the Giant's Scar fast travel point and go northwards. This time he's in a cave, so don't let that confuse you if you're looking for his marker. It's not hard to find but you can miss the cave entrance if you don't keep an eye out.
Xur's inventory of exotic goodies this week includes the Merciless, a fusion rifle that receives a damage buff if you reload immediately after a kill. Non lethal hits also lessen its charge time. The Merciless costs 29 Legendary Shards.
This week Hunters have the option of picking up Lucky Pants, Cayde-6's ones
with an illegally modded holster that are just really lucky. The holster increases Hand Cannon ready speed and initial accuracy. They're pretty good pants, but they were a potential reward for one of the story missions on Titan, so there's a good chance you already have them.
Mask of the Quiet One is a Titan helmet that gives melee, grenade, and class ability energy when you're damaged, and any kills with Void ability regen your health, so it's not to be sneezed at.
Warlocks get the Starfire Protocol chest armour, which gives you an extra fusion grenades, and all kills with the fusion grenade give you rift energy. All of these bits of amour cost 23 Legendary Shards.
Remember that gear you buy from Xur will scale to your character, so only buy from him with your most powerful Guardian.