Saying Yor and ward are the same person just doesn't add up. In Thorn 1. The man Held a "Rose" (Presumably a Gun) which turned into Thorn. In Last Word 3. Jaren Ward held The Last Word right up untill hos Death. Shin evenstates that he hears it fire off and then hears a much "darker" shot, assumedly from Thorn. Keep in mind that in Thorn 2, Yor murders 3 people with Thorn. These three people are mentioned in Last Word 3, Shin states that their death had everyone on edge, even explicitly stating they were gunned down. I belirve that Jaren, being an amazing hunter that was looked up to, was chosen to lead a fire team in hunting down Dredgen Yor. When Yor murdered three of his team, he went off to confront Yor on his own ("probably because he didn't want to see any more dead kids"). Jaren lost the duel and died there. His body and Ghost was soon found by Shin, and the Ghost spoke to Shin, implying that Jaren is dead because the ghost never spoke to anyone but Jaren. Shin then inherits Last Word and uses it to kill Yor.