In this quest you avenge the death of Kadlak who was killed during a forsworn raid. You also take back the shards of Wuuthrad that they took with them.
This quest mainly takes place at Driftshade Refuge which you can find south-west of Winterhold:
In it you find a number of forsworn. The only ones that will give you trouble are the forsworn that have shields and armor. The other die very quickly and don’t deal much damage. I also found that the enemies that do have shields tend to stand around and block you a whole lot. That makes them easy to kill as you can bash them without them dealing damage to you.
If you are having trouble with this quest I suggest that you sneak and use a bow and arrow.