This theory was inspired by the nature of the Cryosthesia 77K sidearm, and also three other Exotic weapons that also occupy the "Kinetic slot": Malfeasance, Thorn, and Witherhoard. Ever since it was announced we were getting Darkness subclasses, alongside the discovery Necrotic Grips could synergize with Thorn, a lot of people have speculated that Bungie was hinting at a "Necrotic"-type Darkness subclass. Meanwhile, the Witherhoard shoots Taken blights, a distinctly Darkness-themed weapon, and the Malfeasance was described by the Drifter as "weaponized heat death" aka. an entropy-based weapon, something which fits with the Darkness' tendency towards reducing systems down to their simplest state. A part of me has wondered for a while what would happen if Bungie decided to change a weapon like Thorn into one of the new Darkness subclass types once it came out. I think Cryosthesia 77K has provided the answer: they'll give weapons like Thorn the new element type, but keep it in the Kinetic slot. This makes sense to me because, from a certain point of view, it wouldn't make sense to have Darkness subclass weapons in the Energy slot [i]because Darkness abilities are "anti-energy".[/i] They remove and reduce the energy in a system down to simpler states. They remove it entirely, creating perfect crystals (Stasis); they break it down through decay (Thorn); they convert living beings into a "perfected, final shape", a process which converts matter into sterile neutrinos (Taken). From a design perspective, separating Darkness weapons into the "Kinetic" slot would help ensure your Energy weapon slots don't become too over-crowded (i.e. you won't need to crowd a weapon of each subclass in there with only four slots to spare) and allow you free use of multiple elemental types, as we're already experiencing with Cryosthesia 77K. On the other hand, Salvation's Grip has shown that Darkness elemental weapons will also be in the Power Weapon slot. Given the 12 weapon types between Kinetic and Energy weapons vs. 5 weapon types for Power weapons, I think there is no over-crowding issue here. We'll have to wait for Season 15, when we'll finally get Legendary Stasis weapons, to see if this theory turns out to be true or not. But if it is, we might see older exotics like Thorn, Malfeasance and Witherhoard undergo element changes when the Darkness subclasses they align most with come out.