The powers you were born with are a curse, as to why you were born with them, that’s another story. Perhaps you were affected by an aberration such as an aboleth before you were born. Or maybe nothing happened, you’re just unlucky, too bad. Sorcerers like these are looked upon with disgust by other sorcerers. Sucks to be you.

Abomination sorcery

Your infected body reacts when you cast magic, upon casting a spell of first level or higher, tentacles sprout from your back for a moment. As a bonus action you can immediately move 5 feet times the spells level.

Tentacles of fear

The tentacles that sprout from your back are extremely frightening, as a bonus action you can summon the tentacles and expose them, you gain advantage on charisma (intimidation) checks, but disadvantage on all other charisma checks. These tentacles last and remain visible until you use another bonus action to dismiss them.

Dexterous tentacles

Your tentacles have become a part of you, and you’ve learned to accept it, you can use them as if they were extra hands. While they are exposed you can use them to perform somatic components of spells, wield items as if you have one extra hand, and they have give you a climbing speed of 30 feet.

Feelers

You have learned to use your tentacles and the rest of your body to sense what’s around you, you gain a blindsight of 5 feet.

True abomination

Your abomination of a body becomes much more powerful as you become one with the abominations. You no longer need to sleep, breathe, or eat to survive. You gain a swim speed of 30 feet. You gain resistance to necrotic and poison damage as your body becomes resistance to those terrible powers. You become immune to the frightened and charmed condition as you have little life left in you. Your body becomes abominable, you no longer can be stunned and are immune to exhaustion.

Wrath of the depths

Your tentacles become even more powerful and you can use them to restrain creatures. As an action plunge them into the ground. Choose a number of creatures on the ground equal to your proficiency bonus, they are restrained until the start of your next turn. If they are underwater the tentacles also release ink, any creature affected by this feature while submerged is also blinded for the duration.