I want him fastened to the wall so he can't escape by pulling free, and so that he can be held up by the nails, not fall down the moment he passes out.
How is my rather insane villain going to make that happen? How is the people saving this poor boy going to get him down from the wall? And how can they treat his wounds before sending him off to the hospital? What will the after effects be (my villain will be careful not to hit arteries or ligaments or other important bits)?
EDIT: New idea: suspension. If someone who has never suspended before is hooked up under the roof in a normal superman suspension and left to hang for an hour or so... what will the after effects be? How will the wounds be treated and how will he be able to move a few days after the incident, if he gets treated at a hospital? Will he be able to move normally by the use of painkillers or not?