Fiendish Legacy: Level 1
You have Resistance to Necrotic damage. You also know the Chill Touch cantrip.
Fiendish Legacy: Level 3
You learn False Life.
Fiendish Legacy: Level 5
You learn Ray of Enfeeblement.
Infused by the Shadows of the Far Realm
Tieflings who have the chthonic legacy feel not only the tug of Carceri but also the greed of Gehenna and the gloom of Hades. Some of these tieflings look cadaverous. Others possess the unearthly beauty of a succubus, or they have physical features in common, with a night hag, a yugoloth, or some other Neutral Evil fiendish ancestor.
As an Chthonic, you have these special traits.
You have Resistance to Necrotic damage. You also know the Chill Touch cantrip.
You learn False Life.
You learn Ray of Enfeeblement.