The Demon's Quest

First, you call upon your shadow blades, mysterious beings of evil magic that take the form of knives and do anything you tell them to. There are 7 of them originally, but you can conjure up to 1,000 if you like. Today you call out 10 of them. "Blades 1, 2, 3 and 4, pin him to a nearby tree." By now the rest of the villagers have arrived, and they watch helplessly as the man is stuck onto the tree like paper onto a corkboard. "Brother!", calls out one of the humans, and rushes out to save him. He tries to pry the blades loose, but only suceeds in burning his hands. You order one of the blades to push him back with the others, and you create a shadow barrier around them, so they can't go anywhere. You turn the shadow blades into real knives, and begin to throw them at the poor man, hitting him just inches away from vital areas on purpose, so he feels a great deal of pain. His screams were heard for miles around, and finally, as the last blade was thrown deep into his chest, right next to his heart, the screaming stopped, and he hung limp from the tree. "This man is an example of what will happen to you if you disobey me. His body will hang here for the next 100 years, never rotting, staying just as it is today, the expression on his face never changing, and yet the blades will be removed and be replaced with wooden stakes." Just as you said wooden stakes, 4 of them appeared where the blades were, yet the blades were gone.