The Destiny 2 Xur May 22 location is on Nessus up on the barge in the Watcher's Grave. Land at the northeast point and hop up onto Calus' barge. You'll find Xur outside on the top deck. He'll stick around until reset time on Tuesday, May 26.
Here's everything Xur is selling this weekend. Remember that even if you already own all of these Exotics, you can still buy them again for a better stat roll.
- Exotic Weapon - Cerberus +1: this quad-barrel auto rifle deals massive damage but has short range and a wide spread like a shotgun. Cerberus is one of the most unique Exotics in Destiny 2, and its Exotic catalyst - which lets you turn it into a veritable shotgun - makes it totally worth using in many activities. It could almost pass for a Borderlands gun, frankly.
- Hunter Exotic - Celestial Nighthawk: Golden Gun deals one high-damage shot. This has been a staple Hunter DPS Exotic for years, and for good reason. A shot from Nighthawk can one-shot most anything, and instantly take a huge chunk out of raid bosses. It's the highest burst DPS possible, so if you don't have it, you should definitely buy it.
- Titan Exotic - Mask of the Quiet One: taking damage grants ability energy, and when your health is in the red, getting kills will heal you. Mask of the Quiet One is let down by how minor its effects are. The bonus ability energy is very minimal, and while the healing effect sounds nice on paper, it only affects the red portion of your health gauge, not your shield. It's a hard pass unless you're filling out the collection.
- Warlock Exotic - Karnstein Armlets: melee kills instantly restore a chunk of health and grant health regen for a short time. Karnstein Armlets look cool and they enable aggressive melee play, but they don't synergize with any of the elemental Warlock melee abilities, so it's still a niche Exotic. If you just want to cosplay a Titan on your Warlock and punch things all day, or you're hurting for a regen effect, you could certainly do worse.
Destiny 2 was recently confirmed for next-gen consoles.