Mephistopheles

As Lord of the Eighth Hell, Mephistopheles rules the realm of Cania. In its cold depths he oversees the suffering of the damned with his gelugeon servants. His ultimate goal is to become Lord of the Ninth and to obliterate Asmodeus, the current Lord of the Ninth.

Personality
Mephisopheles is as evil as he is cunning. He is so good at the art of deception that his plots are meticulously made spanning centuries and entire ages of existence. He cares not for the troubles of others only on what concerns him and his desires. He can also appear very charming and witty, but secretly his rage and his inability to control it fuel his motivations. Needless to say, he has a short temper.

Appearance
Nine feet tall, with hell-red skin bat wings, white eyes, horns jutting from his forehead, and straight, black hair, Mephistopheles plays up his appearance to be as consummately diabolical as possible, He swathes himself in flowing black capes and wields a three-pronged ranseur.

Mephistopheles constantly adopts new symbols. His current one is a red hand with black fingernails shrouded in dark flames.

Twilight War Activities
In the year 1374 DR leading up to the Spellplague, Mephistopheles became heavily involved in manipulating events to his liking. Through the power of the Source, his son Magadon Kest became trapped in his own mind. This allowed the Lord of Cania to manipulate Magadon's thoughts. When Erevis Cale and Drasek Riven arrived to free him from Netherese imprisonment, Magadon inadvertently sent them to Cania where Mephistopheles made a deal that would change the realms forever. The deal was that in exchange for Magadon's life, Cale must bring a piece of the divine essence promised to Mask. When it was all said and done, Cale delivered on his promise which resulted in his death. Mephistopheles absorbed Mask's divine essence and further plotted to increase his power.

Recent Activities
Recently, Mephistopheles was summoned by the Shadovar, specifically Brennus Tanthul. The shade wanted to know the person responsible for his mother's death. Confident in his subordinates' abilities to keep the archdevil bound, he questioned Mephistopheles. When the Lord of Cania had had enough, he broke free and nearly strangled both Vincent and Ilen to death. Once Mephistopheles was completely in the Material Plane, Drasek Riven appeared and forced the devil to retreat back to his native realm. However, as he was leaving he made sure to tell Okeer that he will make sure he gives his regards to his brother in Cania.

Sources:

Book of Vile Darkness

Twilight War Trilogy by Paul S. Kemp