Molag Bal

Molag Bal is the Daedric Prince whose sphere is the domination and enslavement of mortals. His only desire is to harvest the souls of mortals and to bring mortals souls within his sway by spreading seeds of strife and discord in the mortal realms. He is a Daedric power of much importance in Morrowind, where he is always the archenemy of Boethiah, the Prince of Plots.

Appearance and personlity
Molag Bal resembles a large, bipedal crossbreed of a monkey and snake, and usually comes in a form adorned with horns, claws, and a long tail. His scaly appearance is matched by his demeanor, seeing as how this serpentine Daedric Prince is the master of corruption, the King of Rape, and his entire realm of Coldharbour in Oblivion consists of nothing but death and destruction.

Plane of Oblivion
Molag Bal's plane of Oblivion is Coldharbour. The book The Doors of Oblivion says that his plane resembles a copy of Nirn, including the Imperial Palace, but desecrated and ruined. The ground is sludge, the sky is on fire, and the air is freezing.

History and legend
He is the main source of the obstacles to the Dunmer (and preceding Chimer) people. In the legends, Molag Bal always tries to upset the bloodlines of Houses or otherwise ruin Dunmeri 'purity'. He is also the god of rape and is said to be the father (along with Vivec, whom he seduced) of a population of mutant degenerates living in the Molag Amur region of Morrowind. Most disturbingly, this race may have been the first eventual vampires, a corruption of Vivec's ties to the Heart of Lorkhan transmitted to mortals. It is possible he assisted Jagar Tharn in his temporary procurement of the Imperial throne. He was also responsible for the destruction of a city at the end of the First Era.

The Hero of Daggerfall as well as the Dragonborn received Mace of Molag Bal in exchange for eliminating a heretic mage or priest, respectively.

Trivia

 * The name 'Molag Bal' and his believed involvement in the creation of the first vampires may be based on two of the three angels in vampire lore, 'Moloch' and 'Ba'al', whom turned away from God and bear similar genealogical traits, desires and physical appearances to the Daedric Prince.