1st Level Traits

Blasphemed Words. You speak words anethema to the divine to counteract their magic. When you would make a saving throw against a spell or effect of divine origin you may use your reaction to add a +2 bonus to the roll.

Felcasting. You learn one cantrip of your choice from thaumaturgy or a damaging cantrip that does cold, fire or necrotic damage. You use your highest ability Mod as its spellcasting Mod.

Fel Endurance. You cling tenaciously to the last shreds of your life force. The DC for death saves you roll is 9.

Fel Form. Part of your body has an obvious, fiendish appearance. Your hands end in razor-sharp claws, you have hooves instead of feet, sharp teeth fill your mouth, or a whipping tail extends from your spine that can be used for unarmed strikes. The natural weapon deals 1d8 + mod piercing, bludgeoning or slashing (chosen when is trait is picked) damage on a hit and has the finesse property.

Fiendish Resistance. You have resistance to your choice of cold, fire, or necrotic damage.

5th Level Traits

Devil in Plain Sight. As an action, you can hide your fiendish nature. Your obviously fiendish traits disappear, including any tails, horns, and cloven hooves, though hints remain (claws turn into jagged nails or eyes retain an odd hue, for instance). You're still recognizably yourself, but now appear as a typical, non-feltouched member of your base lineage. While in your shapeshifted form, you can't use unarmed attacks, innate spells, or other abilities that require physical features you receive from a fel-touched lineage trait—for instance, you can't use the Fel Form trait. You can remain in your alternate form indefinitely, and can shift back to your tiefling form by using this action again.

A suspicious creature can make a perception or investigation check against your passive deception to discern your true nature.

Devilish Wiles. Traditionally, devils are exceptionally good at persuading people to do things, even when their targets know it's a bad idea. You're also rather good at it, compelling the weak and weak-willed to your bidding. You can cast charm person once per long rest. You use your highest ability Mod as its spellcasting Mod.

Skillful Tail. You've always had a tail, but with practice, you've learned to use it for more than signaling your mood. It has a reach of 5 feet, and it can lift a number of pounds equal to five times your Str score. You can use it to do the following simple tasks: lift, drop, hold, push, or pull an object or a creature; open or close a door or a container. Your DM might allow other simple tasks to be added to that list of options.

Your tail can’t wield weapons or shields or do anything that requires manual precision, such as using tools or magic items or performing the somatic components of a spell.

9th Level Traits

Fel Arts (Requires Felcasting). The Fel Magic in your blood grows stronger. Choose one 1st-level spell and one 2nd-level spell that do cold, fire or necrotic damage or are on The Fiend Warlocks Patron Spell list. You can cast each of these spells once per long rest using your highest ability Mod as their spellcasting Mod.

Fel Wings. When you take the Attack action on your turn, you can replace one of your attacks to call forth bat-like or otherwise fiendish wings from your back, similar in appearance to those of your fiendish origin. Once manifested, these wings remain for 10 minutes. You gain a fly Speed equal to your walking speed Speed while you've manifested your wings.

Light from Darkness. You've battled the fiendish power within your nature and come out on top; whatever you decide to do with your life, for good or evil, will be your choice and your choice alone. This struggle has granted you powerful resistance against the divine. You gain a +2 bonus to saves against any divine effects.

13th Level Traits

Fel Mastery (Requires Fel Arts). The Fel Magic in your blood grows stronger. Choose one 3rd-level spell and one 4th-level spell that do cold, fire or necrotic damage or are on The Fiend Warlocks Patron Spell list. You can cast each of these spells once per long rest using your highest ability Mod as their spellcasting Mod.

Fel Strikes. Your festering connection to fel forces infuses your weapons with debilitating malevolence, tearing down creatures of good with every attack. Your weapon and unarmed attacks deal 1d2 additional necrotic damage to creatures infused with positive energy.

Finest Trick (Requires Devil in Plain Sight). Many fiends can take on the forms of others. With practice, you can do the same. When you use Devil in Plain Sight, you can alter your appearance to match a generic member of your base lineage, rather than one that's obviously you without your fel-touched features. In addition, you can imitate a specific person's appearance (of any lineage of the same size and kind as your base lineage) if you consume a bit of their blood, a lock of their hair, or appropriate equivalents as part of the action. You still must know what the creature looks like, and you must be aware that the consumed portion comes from their body.

17th Level Traits

Dominion Aura (Requires Blasphemed words). For a short time, you fully manifest the expectations of the fiend others see you as. All creatures within 10 feet of you must make a Con Save or take 8d6 force damage with and be knocked prone, taking half on a success. For 1 minute, any creature who ends its turn within the 10 feet of you must make a Con save or 5d6 force damage, taking half on a success. The DC of this ability is 8 + PB + your highest ability Mod.

Once you have used this ability, you cannot use it again until you finish a long rest.