[@thewizardguy] He needs to touch the person and remain in contact for a few seconds. If it is on a being that can sleep, but does not naturally need sleep, it will take a longer time period to put them to sleep. If they physically can not sleep, it's impossible to put them to sleep. If you are put to sleep, you can fight your way out of the nightmare if you can get yourself mentally strong. If contact with Nightmare is broken then it is also resisted, because nightmare has to maintain a concentration while putting someone to sleep. He can't be putting someone to sleep and fighting at the same time.