According to the grimoire this gun is made by following certain steps in a book written by oryx himself. Since we don't learn of the gun itself until eris presents the frame, and she gives us the task of acquiring the three elements of the gun first, would it be safe to assume that she has the book? Btw it's awesome Edit: Also what of the blade? It's position near the end of the barrel could be similar to the Traitors Die. It could also explain why, similarly, the red death looks the way it does. This is a stretch, but most weapons that have something affixed to their barrel are "guardian killers." The WoS being direct links to oryx, and the Monte Carlo and red death having exotic abilities that return power to the guardian who is able to slay with it. Just a few thoughts.