Isn't Mercy stated to belong to Strife, another of the horsemen? In his concept art, the gun in Strife's right hand certainly looks extremely similar.
Its suggested that Mercy IS Strife's gun and Ulthane made a copy for War.
According to the Game's manual Mercy is "The personal handgun of the horseman Strife". Ulthane is suggested to have been the forger of the weapons of the horsemen, So the one in game is likely just a copy. It gives meaning to the achievement it unlocks, "An Old Friend". Would make sense.--Whitedragon254 21:47, January 28, 2010 (UTC)
Ulthane didn't make a copy for it was too fiddly for him to do. Pi face dude 12:43, May 22, 2010 (UTC)
Ok, having played the game again today, I've realised two things:
1. Ulthane is not hammering on Mercy. He's just smithing because that what he's always doing. You can see from the angle he gets Mercy from that is on one side, where he was presumably waiting for War to come back and had it ready to give to him.
2. Ulthane didn't make this gun, therefore it is not a replica (which would be a needless thing to have in the game anyway, and is backed up by the weapon's description in game). His dialogue clearly shows two things: a) that he admires the workmanship (he's bound to have a professional opinion after all - it doesn't mean it's HIS workmanship), and b) it's too dainty for him to use (so why would he have made it in the first place?). I've edited the article to reflect all this. I'm kind of surprised this hasn't been noticed before. Metalmunki (talk) 18:50, April 19, 2014 (UTC)