A tiefling subrace exists for each of the major powers of the Nine Hells. Each comes equipped with unique abilities that give them a different flavor from the vanilla tiefling.
This is the base Tiefling race as described in the Player’s Handbook.
The spells granted are substituted with ray of sickness and crown of madness.
The Intelligence score increase is replaced with Dexterity, and the spells are replaced with disguise self and detect thoughts.
The Intelligence score increase is changed to Wisdom, and the spells changed to friends, charm person, and suggestion.
The Intelligence score increase is changed to Dexterity, and the spells changed to minor illusion, disguise self, and invisibility.
The Intelligence score increase is changed to Constitution, and the spells changed to ray of frost, armor of agathys, and darkness.
The spells are changed to mage hand, floating disk, and arcane lock.
The spells are changed to mage hand, burning hands, and flame blade.
The Intelligence score increase is changed to Strength, and the spells changed to searing smite and branding smite.
With their bonus Charisma and innate spellcasting, Non-Feral Tieflings are best suited to be Sorcerers and Warlocks. Their racial abilities will compliment the class abilities provided by either very nicely. Feral Tieflings are best suited to become Archery Rangers, Fighters, or Rogues. The Infernal Subraces provide a variety in spellcasting and the +1 ability score, which can help you further optimize your caster and the flavor of your character.