Xur is selling Gjallarhorn for the first time since the week of September 19th, 2014 - the second week of Destiny’s release.
Gjallarhorn is one of the most well-known and most sought after weapons in Bungie’s Destiny. This exotic solar rocket launcher comes with Tracking - meaning that its rockets will lock onto and track their target. It also comes with Wolfpack Rounds - meaning the rockets explode into smaller rockets on impact, and each of those smaller cluster rockets will also track the target.
This means that Gjallarhorn does a massive amount of damage to a single target, making it the go-to weapon for burning down the game’s notoriously bullet-sponge bosses.
Because Xur has never sold Gjallarhorn since the second week of Destiny, the only way to obtain the rocket launcher was to get incredibly lucky and see it drop from the Strike playlist, Nightfall, exotic chests, legendary engram, or raid bosses.
The sheer rarity of Gjallarhorn, especially compared to many of the other exotics, has led players to believe that Gjallarhorn had a naturally smaller drop rate than most of its counterparts. The difficulty in obtaining Gjallarhorn has meant that most Guardians, even many who had been playing since release, did not have the coveted rocket launcher.
With Taken King due to release in exactly one month and one day (September 15th, 2015), it seems Bungie has taken pity on the Gjallarhorn-less Guardians and convinced Xur to open his stockrooms. For 17 Strange Coins, you too can now join the ranks of Guardians not turned away by ‘LFM for NM VoG, must be 34 and have Gjallarhorn’.
Unless, of course, you’re not 34. Slacker.
