There is a ton of confusion over the Jaren Ward/Dredgen Yor/Shin Malphur/Last Word/ Thorn. But the most reasonable explanation "imo" is that Jaren Ward arrives at Palamon (idk what reason) and then everyone comes to view him. Young Shin Malphur comes to get a close look and Jaren Ward offers him the Last Word. (I think he did this because he already had Thorn at this time) Young Shin Malphur refuses, but like he said, it wasn't the last time he held it. As the Thorn slowly corrupts him, Jaren Ward turns into Dredgen Yor, (I think this because they both we're considered beacons of hope, but it says that Dredgen Yor is the "first and last descendant of the name Yor" during this transformation. (Also if you think of it Dredgen Yor and Jaren Ward kinda sounds similar) Dredgen Yor starts killing random townies of Palamon, and Magistrate Loken takes this into notice. Then Loken, and his nine men, confront Jaren Ward/Dredgen Yor, everyone thought that it was just because Magistrate Loken was corrupted, as Shin Malphur notes, he remembers the Last Word being lightweight, so it wasn't the first day Jaren Ward came he was confronted. Corrupted Jaren Ward kills the ten people and probably massacre the rest of the town (not in the time ofc) except Shin Malphur. Shin Malphur probably trains himself (because he wasn't even born a Guardian) and then confronts and kills Dredgen Yor on Dwindler's Ridge. Also I believe this is how it went down because if Dredgen Yor killed Jaren Ward, it would cause an uproar, because Shin Malphur said that he was one of the very best Guardians out there, and if he was murdered, it would've been mentioned more. BUT YES AGAIN, this is all opinion.