Mephistopheles

Lucifer Morning Star, The First Devil King, Lord of the Hells, Judaean Lucifer, The Great Deceiver, and Prince of Darkness
Alignment: Lawful Evil
LORE: When the Greek deities left the realm of Earth for the Crossroads, all that was left was Chaos, and her Divine Celestials. One of them grew tired of her, and tried to rebel, and he was cast out from the heavens to rule the hells. Few people know this, but there is an underworld, and there are hells.  The Hells were shaped by its rulers, and when he was cast out…he formed this realm. Many believe he does leave his realm, but that is a farce. Whenever doubt is present, he is there to make a deal. Though he would never engage in the politics of the gods, he enjoys building an army of fallen heroes. Some he respects, but all he owns for eternity.
One of the 5 Devil Kings, Lucifer, is the most powerful devil of the kings.   When he fell from grace, he quickly conquered and tricked all the other devil kings into acknowledging him as high king.   The ones that didn't fall are the other four kings of the 5 kings of hell, and forever at war they remain.   With the creation of the Greater Key, the 5 devils are bound to make a contract with the person holding the book, but anyone foolish enough to make a deal will surely see themselves bound to one of the respective kings. —Hecate.
Personality Traits: To see him upset would be your downfall, but he is calm, manipulative, and an exceptionally good liar. Hide your lies in the truth.
Ideals: I will rise above my mother and assume the role of the Creator.
Bonds: His wife Urilana
Flaws: Physically weaker than most deities, and in general will always lose to his mother.
Symbol: The Morning Star
Worship:

• Gain more followers and indulge in life.

Perks

Gained When Selected
Ability Score Increase: Increase Charisma by +2, Constitution and Intelligence by +1. +10 to Persuasion
Mark of the Beast: Feat You take a mark, forever binding you to him, and in return you gain use of the Wish Spell.  This wish is your contract, and unless you are released from your contract, you will forever become one of his warriors in the afterlife.
The Archdevil: Feat As a servant to Mephistopheles, you are granted the ability to turn into an Arch-Devil but doing so will subject you to the will of Lord of Lies.  You May use this once per long rest but it grants you the following benefits.

• Resistance to Radiant and Necrotic Damage.
• Immunity to Poison, Blindness, Deafness, Broken, Bleed, Disable, curse, and Patron Curse.
• Immunity to non-magical melee damage
• Gain beautiful white wings with a flying speed equal to your movement.
• Immunity to Hellfire and fire damage.

Hellfire: Once per day you may use the spell of your master to crush your enemies.
Hellfire: 9th level Evocation Casting Time: Action Range: 60ft Components: V Duration: Instant Hellfire rains down from the heaven hitting all targets within 60ft radius for 10d8 radiant, 10d8 Necrotic, and 10d8 fire damage, level 3 burned, doomed, cursed, and patron cursed to all creatures that fail a dexterity saving throw. This does triple damage to structures. On successful saves, the damage is halved, and no ailments are taken.