I have a pretty neat little story about a Vampires, probably someone has had something like this before already, but I thought it was pretty awesome and I'd like to share. Anyway, here goes:
"Sit, little Urist and let me tell you a bit about the history of our fortress, Konosolin, the Brasstongs. You see, it wasn't always the bustling dwarven metropolis you have known for all seven years of our life. When I came here many years ago, it was still an outpost with only some twenty odd dwarves scratching their livelihood out of these barren rocks. A few years before, it was only seven brave pioneers who laid the foundation of this great city. At the time I arrived here, we still had one of those original seven as our leader. A brave and wise dwarf I ever I've seen one, not like the wimps you young folk elect every year these days. But I digress. See, a few years earlier, dwarves had begun to vanish mysteriously. Ever so often we would find someone's body... drained completely of blood. First it was our Mason, Cilob Regdeg, one of the original seven. A dwarf that had worked hard to make many of the wonderful doors, thrones, and tables we still use to this day. A few months later, we found Litast, a Fisher, also completely drained of blood. Again a few months later, it hit Inod, an experienced Armorer, that proved to be a harsh blow to our fortress in the goblin invasions that would follow very soon.
But I'm getting ahead of myself. This time, our wise leader decided he'd had enough. And this time, we actually had someone who claimed he had seen the whole thing. He claimed that one of our hunting squad had killed poor Inod in his sleep after a hard day at the forge. But when he reviewed the personal files we get on each dwarf from the mountain homes, our leader found that that the witness, Èrith Logemsigun, had lived in over twenty different settlements before he immigrated to Konosolin. Seeing this, he decided in his great wisdom that it was very likely that Èrith had done the bloody deed his very self."
"Even though he had no hard evidence, he convicted him anyway. Now I know that many of you young people call this period the dark times of our fortress, because you claim that our wise leader wasn't elected by the will of the people, and that he had used oppressive and dictatorial means. Humbug I say! Those were the glory days of old when a leader took swift action for the best of his people. He did absolutely right in convicting Èrith as you will soon see."
"You see, in those days, we didn't have the lavish prison next to the dining hall. That is a place where the young ones even like to try and sneak into, because they marvel at the craftsdwarfship of the golden chains, and the comfortable beds. No, in those days, we had nothing but two leaden cages we bought from the Elves a few years before. It was one of these very cages Èrith was locked away in. And since he was still unsure, our leader ordered walls to be constructed around these cages. A door was placed and firmly locked, to see if Èrith would cry for food after a while. But even after almost a month into his prison sentence he wouldn't display any signs of malnourishment. Not easily fooled, our leader concluded that he must be a blood sucking fiend, responsible for the others as well, and swiftly sentenced him to jail time for these deeds as well."
"By the time he had done about two thirds of his time, a change of heart befell Èrith. He rued what he had done, and yet he knew his vampire nature would drive him to do it again if he was to be set free. So he asked our leader to be drowned in a pool of hot magma as is still our custom for the most vile of crimes, such as being a goblin. But our leader hesitated. You see, Èrith was a famous black smith at this time already - he created Ariseth, that very marvelous bronze statue of the founding of our great metropolis that we have in the statue garden near the living quarters. So our leader announced that he couldn't stand to waste such god given talent for craftsdwarfship. Yet he couldn't allow Èrith to go free once again and continue his murders."
"What our wise leader did instead is this. He had a complex of chambers excavated deep in the bowels of the earth near the magma pipe. A table and chair was placed there, and a bed as well. Also a magma forge with only the finest tools. A crafty system of dump chutes leading in and out of the complex was devised. Finally, we would place Èrith's cage in there and hook it up to a lever outside, and then seal off the entire complex with thick granite walls. When the lever was pulled, Èrith's cage opened and he was set free, to wander these quarters, but not to leave it ever again. He has a dining room, yet he never eats. He has a bed, but he never sleeps. He just dwells there, brooding, in the dark, and ever so often, a bin with bars would come down the chute, with instructions on metal items he can make, to enrich our fortress with the beauty of craftsdwarfship, and to atone for his sins. They say his craftsdwarfship has even improved in his isolation. Some say it's because smithing is all he ever does, but I believe that it's his way of speaking to the outside world. He can never directly speak to a living dwarf again, so he uses his ornamentation to tell his fellow dwarves he's sorry for what he did, and he's trying his best to be an honor for dwarfhood."
"Your stories are stupid, grandma. Everyone knows vampires aren't real. No dwarf can live for years without eating. Why even a few years ago Cilob's uncle starved to death while excavating a drainage pipe. There's no way we have an undying master blacksmith here."
"Oh really? Have you ever wondered why not a single dwarf in this fortress has any experience or interest in blacksmithing, yet our dining hall is full of master work metal furniture and our baron sits on a golden throne? Have you never wondered why sometimes we ask you to drop a few bins with bronze bars in that dark hole far down in the earth? And have you never wondered why sometimes we ask you to pick up masterful bronze furniture from that tiny room even further below? And have you never noticed the moans in the staircase wall next to the old magma forge?"
tl;dr: Had legendary vampire blacksmith, sealed him off in a small room and had him make masterwork metal furniture for the rest of his life time. Planning to train another vampire as gem setter BTW.