Mephistopheles, the King of Hell, was a character on Xena: Warrior Princess. He was the Royal Ruler of Hell, until Xena killed him and forced Lucifer to take her place as the rightful ruler of Hell.
Mephistopheles ordered Callisto to kill Julius Caesar and make Xena follow the path of peace that Gabrielle was following at the time, in order to have a chance of resurrection. She failed and inadvertantly caused their deaths, which led to Mephistopheles to turning her into an Archdemon. Mephistopheles remained silent during Callisto's subsequent redemption and a demonic Xena's failed invasion of Heaven- it is not clear to what, if any extent, these events fitted into his plans.
Powers and Stats
Age: Unknown, many millennia old at least
Powers and Abilities: Superhuman Physical Characteristics, Immortality (Type 1), Illusion Creation, Telepathy (Can project images into the minds of others even through other people), Possession, Telekinesis,, Teleportation, Levitation, Weather Manipulation, Can conjoin the bodies of others (He forced Xena and Gabrielle to stick together), whoever kills him must take his place as the King of Hell (but this can be bypassed by having someone else take their place), can control evil spirits, dimensional manipulation, can attack from across dimensions
Attack Potency: City level (Caused a storm with his presence, which stopped when he was killed)
Speed: Superhuman, Subsonic reactions
Lifting Strength: Class 5 via power-scaling
Striking Strength: Unknown via power-scaling
Durability: Building level via power-scaling
Range: Several meters, several kilometers with storms, cross-dimensional
Standard Equipment: His trident
Intelligence: Fairly intelligent, reigned as the King of Hell and saw all that was happening on Earth, concocted a plan to make himself flesh
Weaknesses: Nothing notable
Notes: Not to be confused with the similarly - named characters from Saint Seiya and Marvel Comics