Please note that this is the Narutopedia's article on the original Dead Soul Technique. If you are looking for the article on the similarly named video game-only ninjutsu then you should head to Forbidden Technique: Dead Soul Technique.
Using this technique, a person can temporarily reanimate a corpse, creating the illusion of a living person, and manoeuvre it at will with chakra. This is achieved by causing the heart to beat once more. The reanimated corpse can serve as either a short-time ally or an effective decoy. The said corpse can also use techniques. The traces of surgery can also be erased with chakra, because of which there's no difference, at first glance, with a live person. Kabuto adds plastic surgery to this, altering the corpse's face, and goes even further by erasing its bodily odour, so that the smell doesn't give him away, thus creating an effective body double for himself.