"When Elves and orcs' bodies are damaged beyond our capacity to repair them, we leave them. We can at that time, if we choose, go to the Halls of Mandos, or we can just sort of drift. You lose yourself, if you choose to just drift. In the Halls of Mandos, Námo, who is a Vala, tries to rehabilitate you and when he thinks the time is right return you to a body. People who he disapproves of don't tend to get to come back. I think it's better to bring everyone back, personally, and then resolve problems of antisocial behavior in some less dramatic way, but it will certainly cause political upheaval. I know nothing about orc social structures or what happens if you bring orc dead back to life."