Armerane tries to keep it mostly quiet, but during his childhood, a traumatic event resulted in a split within his mind. This alter has refused a name, seeing it as unimportant, but Armerane usually just calls them his Other. Being the more outwardly confident member of the system, the Other is often the one to handle interpersonal situations with people that aren't Armerane's closest family or friends, and the difference in demeanor has earned him the odd look.
The Other is more outgoing, but also more prone to emotional "knee jerk" reactions, always being just a bit more defensive or apprehensive. Often, Armerane needs to remind them from the backseat to ease up on the throttle, so to speak. Usually this works out, but when it counts the most, the Other has been able to spot trouble and stick to their guns very consistently.
Being an alter, the Other can do much of the same things Armerane himself can when it comes to defending themselves. However, due to their more closed-off nature, the Other prefers a more direct approach by using more innate elemental magic from their spellbook, using the riftcaller as a more traditional dagger. Carving the dirt beneath people away as a trap, forming stone into barriers, and tossing rocks are all fair game.