The Tieflings connected to Nessus command the power of fire and darkness, guided by a keener than normal intellect, as befits those linked to Asmodeus, King of Hell, Chief of the Lords, Lord of the Ninth and Archduke of Nessus.
ability score increase:Your Intelligence score increases by 1.
race features: Legacy of Nessus: You know the Thaumaturgy cantrip. Once you reach 3rd level, you can cast the Hellish Rebuke spell once as a 2nd-level spell. Once you reach 5th level, you can also cast the Darkness spell once. You must finish a long rest to cast these spells again with this trait. Charisma is your spellcasting ability for these spells.