Sinner's Senses

Your fiendish bloodline gives you access to certain traits. Starting at 1st level, you have darkvision with a range of 60 feet, and magical darkness does not impede your darkvision. You can see normally in darkness.

You also gain telepathy out to 60 feet. You have to share a language with the creature to be able to communicate with it. You can share simple ideas with creatures that don't know a language through telepathic images and sounds.

You also learn to read, speak and write Infernal or Abyssal.

Hellish Harm

At 6th level, you learn to use your innate raw magic to inflict further damage with your spells. When you cast a sorcerer spell, you can expend spell points to gain a 1d4 fire damage bonus per spell point. The fire damage dealt with these spell points ignores resistance.

At 18th level, your hellish harm die becomes a d6. The fire damage dealt with these spell points ignores immunities as well.

Wings of the Wicked

Starting at 14th level, you gain the ability to sprout a pair of fiendish wings from your back, gaining a flying speed equal to your current speed. You can create these wings as a bonus action on your turn. They last until you dismiss them as a bonus action on your turn.

You can't manifest your wings while wearing armor unless the armor is made to accommodate them, and clothing not made to accommodate your wings might be destroyed when you manifest them.

Soul Scorch

At 18th level, you learn to truely devastate those that oppose you. As a reaction upon being hit by an attack, before damage is rolled, you can unleash a fiendish force instilled in you to harm your assailant. You reach out to their soul and set it ablaze, causing flames to leak from the creature's eyes, ears, mouth, nose and wounds.

The creature takes 10d10 fire damage, ignoring resistance and immunity, and the creature must make a Constitution saving throw or suffer a level of Exhaustion. On a successful saving throw, it has disadvantage on the attack against you. Once you use this feature, you can't use it again until you finish a long rest.