The essence of the Bone Stitcher is that is vivisects people and then uses stolen blood and muscle fibers to improve people, finishing up its macabre surgery by covering the recipient's bones in some kind of dark encasing material. This covering makes attacking the Vitals and Brain close to impossible. The recipient is permanently scarred in a hideous manner, but enjoys increased strength, durability and agility.
Of course, it can't give the really fancy and powerful stuff to all recipients of its ministrations, so the usual 'vanilla' variety is detailed below.
The Stitched:ST: 16
Basic Speed: 6 Move: 6 Per: 10 Will: 10
thr: 1d+1, sw: 2d2+2
Injury Tolerance (Unbreakable Bones, No Brain, No Vitals)
Social Stigma: Monster
Skills: Brawling-15, Broadsword-14, Crossbow-15, Polearm-14
Notes: With HP 21, DR 2 and their specific form of Injury Tolerances, the Stitched tend not to suffer crippled limbs- taking 14 damage to lose an extremity. I suspect they'll be great meatshields and frontline troops. Their crossbows are obviously a shoot once and then discard for the rest of the battle weapon- but hitting that 2d+1 to 2d+3 shot (for an +4 ST crossbow at ST 20) is going to hurt, greatly.
I don't think my players will like it when the Stitchers get access to halbreds. 3d+2 impaling damage is nothing to sneeze at, and 4d cut is almost as bad.