Eldritch Bloodline

Even before knowing of your heritage, you always knew you were… Different, and like in a really painful and uncomfortable way. 
You experience night terrors that feel more real than your daily life, see things nobody else can in daily life, and on the rare and especially awful occasion, experience bursts of uncontrollable and vile magical abilities.

You are God’s personal mistake and the spawn of a pit doer than hell itself. You are a spawn of the pit of Tartarus, and that is the source of your magic. Cope and seethe.

Eldritch Incarnation

Whenever you expend all of your sorcery points, you must roll a D20. Anything below a five will have a disastrous affect on you/your companions, anything higher will be beneficial.

Blind Rage

If an enemy lands a critical hit on any of your companions, you have the option to respond the same way you would if you ran out of sorcery points, except your target is specifically the person who landed said hit. The blind rage lasts for 1 turn, during which you deal 5d6 radiant or necrotic damage (your choice) on any successful melee attacks.

Toying with Reality

Starting at 6th level, you have the ability to twist fate using your Eldritch magic. When another creature you are within 20 feet of makes an attack roll, as skill check, or a saving throw, you can use your reaction and spend 2 sorcery points to roll 1d6 and apply the number rolled as a bonus or penalty (your choice) to the creature’s roll. You can do so after the creature rolls but before any effects of the roll occur.

Accepted Fate

At 14th level, you’ve accepted your fate, and therefore are learning how to have a modicum of control over the surges of your Eldritch magic. Whenever you roll upon running out of sorcery points, you can roll a second time if you don’t like what you get, but must use the number you roll subsequently.

Final Form

Beginning at 18th level, the blatantly and viscerally unholy energy of your magic intensifies.

Once per session; the DM will inform you at a time they choose, that you will have to roll a Wisdom saving throw in order to prevent something you don’t fully understand from taking over your body for a very slow, gruesome, turn. Anything below a ten, and good luck, as you’re really gonna need it. Anything above a ten, and any attacks you make will deal 2d6 of radiant and 2d6 of necrotic damage during the next round of combat.

On top of that, anyone who isn’t in your party will have to roll a DC15 wisdom saving throw upon any verbal interaction you have with them. A failed save will give you advantage on all Charisma based rolls, a passed one will give them a glimpse into what you actually are, and they’ll become frightened and immediately exit the situation.