Infernal Bloodline

Your innate magic is almost certainly infernally influenced of fiendish in nature. Pit Fiends, Balors, Imps, and various others from the Hells and Lower Planes of Existence can claim this ancestry, though few choose to. Other casters of this origin have been influenced by beings from beyond the Material Plane; fiends, demons, and other, darker creatures.

Fiendish Fury

Starting when you choose this origin at 1st level, your magic is infused with a ferocity born of your bloodline. Pick a damage type. When you cast a spell that deals damage of that type, you can reroll a damage die and add the new number to the damage total. When a spell that deals that damage type is used against you, you can force the highest damage die to be rerolled, subtracting the new number from the total damage rolled. You can use this feature a number of times equal to your Charisma modifier (minimum of once) and you regain all uses after a long rest.

Infernal Spite

Starting at 1st level, you can invoke the wrath of your ancestry when you take damage from a spell or melee attack. When you take damage, you can force your attacker to take 2d12 damage of the type you selected from Fiendish Fury, ignoring resistance. You may only use this feature once per short or long rest.

Wrath of the Hells

At 6th level, you can expend sorcery points to add extra damage dice to a spell you cast. For every two sorcery points expended, you may add one extra die to the total damage of your spell. You may use Metamagic to alter the spell, in addition to this effect.

Channeled Power

At 14th level, you gain resistance to the damage type you chose, and take no damage from it on a successful saving throw made to reduce damage of that type from an attack.

Ward of the Planes

At 18th level, you gain a heightened grasp of the type of damage you chose at 1st level. As an Action, you can expend 6 sorcery points to wrap yourself in a shield made of pure energy. Hostile creatures that move within 10 feet of you or begin their turn there must make a dexterity saving throw or take 3d12 damage, in addition to your charisma modifier (minimum of 1)or half that damage on a success. This feature lasts for one minute or until your concentration is broken (this does not count against the number of concentration spells you currently have active), and while it is active, you gain immunity to the damage type you chose.