Bloodline of Andromalius

The most numerous are the spawn of Andromalius, the current Lightbringer of the Flames Below. She is a wicked manipulator, often mirrored in her spawn. Misleading, provoking, enticing and placating is second nature to these silver tongued devils. The natural disgust a mortal feels towards Fiends can easily be spun as attraction or fascination by these tricksters. Few minds safe from their deceitful ways and The Serpent's Head has made sure to plant as many of her hidden agents, be they knowing pawns or not, across the world in positions of power.

-Chemardale, The Red Prince

Bloodline of Andromalius:
ASI: +4 Cha
Devil's Tongue. You know the Vicious Mockery cantrip. Once you reach 3rd level, you can cast the Charm Person spell once as a 2nd-level spell. Once you reach 5th level, you can also cast the Enthrall spell once. You must finish a long rest to cast these spells again with this trait. Charisma is your spellcasting ability for these spells.

Serpent's Scion: You are proficient in Persuasion, Intimidation and Performance. You can double your proficiency bonus in these skills. In addition, you can take the Silver Tongued feat for free.