Durok was created by Karnilla at the behest of Loki for no other reason than to destroy Thor. The only way that the Silver Surfer could beat him was to transport him to a far distant future just before the "Big Crunch" and leave him there.
Many years later, Loki would travel a few seconds after Silver Surfer left and rescue Durok. He then tasked Durok along with Fenris to invade Vanaheim. Thor, Sif, Valkyrie, and Beta Ray Bill attempt to stop both of them. During the fight, Durok kills Valkyrie but Sif uses Dragonfang to wound him. Thor then uses chains to control Fenris and attack Durok. A weakened Durok is then killed by Thor who engages him in a fist fight before striking him with a lightning bolt. 
Powers and Abilities
Durok is more powerful than even the likes of the Silver Surfer.