Those of you that dropped the cash required to pick up The Dark Below DLC for Destiny may have come across a rifle by the name of, Husk Of The Pit. It houses the possibility to evolve into the considerably more interesting exotic weapon with an awesome name, Necrochasm.
Locating the Husk of The Pit is as you would expect, a bit of a grind. It may be a common drop but that doesn’t mean you’ll find it easily, chance is a fickle mistress. But you can find it by hunting and killing the Blades of Crota on Earth and The Moon. You can locate the Blades of Crota on either planets on Patrol or you can also come across them by rerunning the Fist of Crota mission. It must be noted that the rifle won’t drop as an Engram. Keep an eye out for the notification since it will be added automatically.
Next you need to purchase an Embalming Orb from Eris Morn for 10 Black Wax Idols, unlocking the Cannibalism perk. Then you need to kill 500 Hive enemies to make the weapon evolve again into Eidolon Ally.
Finally, to get Necrochasm, you’re gonna need to put in some actual effort. You need to get your paws on a Crux of Crota, and that means killing The Dark Below’s Raid Boss on hard mode (Crota’s End) which has not been released yet. Once it’s released you will need to take down another set of hives and achieve The Burgeoning Hunger perk on Eidolon Ally to fully upgrade to Necrochasm.That means, no one has even used Nercochasm yet, but it’s already sought after because of its explosive Cursebringer perk which can trigger a Cursed Thrall explosion.