Skalgor is described as hitting as hard as the Grand Shaman, while running faster than the player! So he requires a team to kill. He also has so many adds that it pays to camp the room rather than face his entire army at once.
The loot is a selection of high level scrolls and potions, including things like cure pots and scrolls of drain life. Bones from Skalgor and his minions can be used to craft some extremely high level shields, depending on what gems you combine the bones with.