I contend they are 2 separate individuals. Jaren died in the woods and his ghost escaped, taking TLW in transmat form to Shin, Jaren's student. This battle is the last time we see Jaren and is presumably when he dies/disappears. So why is it that we hear 2 separate guns, 1 definitely TLW, the other, being a wicked sounding weapon, presumably being Thorn. Thus, considering the timing, it would be impossible for TLW to be "the rose" that preceeded Thorn. The fact that Shin supposedly confronts and kills Yor with Jaren's last words phrase confirms that these are 2 distinct weapond. Additionally, if the two guns are 2 separate weapons, why would Jaren be using both weapons? And one final point, if this was when Jaren converted to the darkness, why would he let his ghost go free with TLW? A ghost that knows all about him and a weapon that is clearly powerful. Just letting these go would be a tremendous risk for him. The more likely scenario would be Yor either corrupts or destroys his own ghost. So, I say again, Yor killed Ward in the forest. Wards ghost, likely unable to revive Ward due to Thorn or simply because Yor would destroy it when it tried, transmatted TLW and fled to Shin so that Shin, Wards student, could take up his mantle. Wards body was never recovered due to the risk of recovering it and the apparent lack of value of recovering bodies in this day and age (think the titan over by the temple of crota). Edit. Also, Yor indicates that he called his weapon the rose because of the bloom when he fired it, but when it was not being shot, it was only jagged thorns. This also indicates thorn and TLW were different weapons, as TLW doesn't have any jagged edges.