- This character's history and characteristics are identical to that of his alternate dimension counterpart up until just before the Dark War, where the timeline split and the following changes took place.
Soon afterwards, Sebastian joined forces with the faeries and stormed Alicante, Alec and Isabelle fought against his forces, however, Isabelle was ended up being killed by Sebastian when she attempted to kill him with the Mortal Sword. Sebastian eventually destroyed the Shadowhunter homeland when he flooded it with demons brought into the world through the blight.
Alec's boyfriend Magnus Bane, a warlock, was one of the first to become sick as a result of the blight, and begged Alec to kill him once he realized he was becoming a demon. Alec granted this request and, knowing that Sebastian was hunting him for his knowledge of the resistance, chose to take his own life rather than be captured and either tortured or turned into an Endarkened.. His and Magnus's bodies were later discovered together in the ruins of New York.