It's Friday, and that means Destiny's mysterious merchant, Xur, is visiting with a new slate of items to hock. There's the usual slate of exotic armor, Three of Coins, and so on, but forget about all that--the real highlight is the weapon he's selling, the Zhalo Supercell.
For those who don't know, the Zhalo Supercell is an exotic auto rifle introduced in The Taken King, and it's both excellent and incredibly fun to use. Both of these things stem from the fact that it's the only primary weapon in the game to do elemental damage--arc, to be specific. Not only that, but the bullets the gun fires have a chance to chain lightning to nearby targets.
You can see what it's like to use the gun in the video above. Needless to say, this is something you'll want to get your hands on. It's priced like a standard exotic weapon: 23 Strange Coins.