Ash

His name is Ash, and he's the grand daddy of all bad asses. Sure he used to be a wussy and let his friend Scotty chop up their friends. But Ash quickly learned. He killed his best friend and killed his own girlfriend. He even went as far as killing his own sister. Of course after they turned into deadites.
Evil found a great opponent in Ash. Evil possessed his friends and Ash didn't have hard feelings about it, he was able to forget about the whole deal. But then Evil took his hand, and made it personal. Decapitating his girlfriend and cut up her body sure fucked up Ash's mind. To save his own life he had to use a chainsaw to cut off his demonic hand. He used that same chainsaw to replace his missing hand.
After the help of Annie and her friends Ash was able to sent the Evil back in time, unfortunately Ash was sent back with it.
Falling from the sky, as prophisised in the Necronomicon Ash battled Evil and the army of darkness in 1300AD England. Ash tought the medieval primitives how to use steam, gunpowder and kung fu. He got a chance to lead them, to teach them. But his place was in the present. He swallowed the juice said the words and returned home.

Other sources will tell you that Ash never returned to the present. Instead he woke up in an apocalyptic London in the future, where Ash realised... he slept too long.

Ash

Profile for Ash:

Name: Ashley J. Williams
Occupation: S-Mart clerk
Known Relatives: Cheryll Williams (sister, deceased)
First Appereance: The Evil Dead, 1982; also appeared in Evil Dead 2, 1987 and Army of Darkness, 1993
Distinguishing features: A metal (right)hand, a scar on his chin
Powers: Near invulnerability, reloading guns without uh... actual reloading
Weapons: A twelve gauge double barreled Remington, a chainsaw, an axe and a Winchester
Special Equipment: A metal gauntlet and a chainsaw that can be placed on his stump

Why Ash is unbeatable: He killed his friends, he lopped of his own hand at the wrist, replaced it with a chainsaw. He build a mechanical hand and fought against a bad version of himself in medieval times and returned home safe and sound. Ash never gives up, and he's willing to win nomatter what it takes. And who would possible want to fight someone who can reload his shotgun with his mind?