Bois de Justice is the guillotine of the French revolution. The main character of Dies Irae gains it as a relic and when activated it makes the arm look like this as well as producing a large curved blade from the elbow. It has the power to kill whoever's neck is cut by the blade regardless of regeneration or immortality. It also has the soul of the girl Marie residing within it, whose curse the blade harnesses for the aforementioned effect.