You can possess him with a few demons. You can chop off his hand. Hell, you can even send him back through time. But the one thing you cannot do to Ashley "Ash" Williams: Keep him down for good.
The same can't be said of Ash's friends, who, in the first two Evil Deads offer up a survival rate of exactly zero. Ash is actually supposed to have died in the final frames of The Evil Dead, but the sequel retcons the whole thing, causing him to re-endure a gory getaway in the forest cabin. In the process, he loses his hand but, hey, chainsaw hands as replacement.
In the final Evil Dead, Army of Darkness, Ash is sent to 1300 AD. His only way to get back to the present time and his job at S-Mart: Going through a horde of the undead (led by an Ash clone) to retrieve the Necronomicon, the book of the dead. Groovy.