Destiny's Xur is back in the tower for a limited time this weekend selling the Thunderlord exotic machine gun as well as the Obsidian Mind helmet. Xur can be found in the tower by the big door near the Speaker, according to VG247.

Xur will only be in the tower until Sunday at 4 a.m. EDT. 

Xur will be offering up several special items this weekend, including one that he has never offered before. 

The Thunderlord exotic machine gun has never been offered by Xur before. The machine gun has a high rate of fire and is very stable. The longer the trigger is held, the faster and more accurate the weapon fires. The Thunderlord exotic machine gun can be purchased for 17 Strange Coins.

The Obsidian Mind helmet will also be on sale. This helmet is only for warlocks, but it's especially good for voidwalker warlocks. 

The Ruin Wings Titan Gauntlets provides 333/366 defense. It has stats of 30/36 for light and 75/113 strength. When equipped, the Ruin Wings Titan Gauntlets causes heavy ammo to drop more frequently and more ammo is included in each drop. It also increases the speed of all Special Weapons. The Ruin Wings Titan Gauntlets can be purchased for 13 Strange Coins.

The ATS/8 Arachnid Hunter Helmet provides 407/447 defense. It has stats of 30/36 for light, 42/73 for discipline and 42/73 for strength. When equipped, the ATS/8 Arachnid Hunter Helmet replenishes Super Energy when an enemy is killed using a grenade. Also the Golden Gun zooms in for accuracy when zoomed in. The ATS/8 Arachnid Hunter Helmet can be purchased for 13 Strange Coins.

The Lucky Raspberry Hunter Chest Armor provides 339/488 defense. It has stats of 21/36 for light and 100/170 for intellect. With the chest armor, more ammo for Heavy Weapons can be carried and the Fusion Rifle can be carried. The Lucky Raspberry Hunter Chest Armor can be purchased for 7393 Glimmer.

The Bad Juju Pulse Rifle will have an upgrade. It has an above average rate of fire (73 out of 100) but a very low impact rating (7). When an enemy is killed, the weapon will reload automatically and increase the damage for a short time. Kills will also help charge the super level.

For the entire inventory of Xur items offered this weekend, visit the Reddit thread.