Corrupted Soul

Where some magical powers flow into souls from dragon lineage, celestial blessings, or other more benevolent or neutral magical beings, it should only be rightly assumed that the magical powers of some sorcerers stem from more diabolical sources. Such souls may indeed be evil themselves, or they are perpetually at war with the evil influences that roar through their spirit. These sorcerers are so suffused with negative energies that they emanate evil auras of darkness and conduct malevolent magic of great power, even if their aims are noble. These spellcasters are renowned for their moments of terrifying power, becoming a horrific display of evil magics and dark powers. Whether they battle their own bloodline to wield such awful power for good ends, or they serve amidst the forces of evil they are kin to, these sorcerers are capable of wielding the bleakest magic, using terror and darkness in addition to magical damage.

Dark Influence
1st-level Corrupted Soul feature

If you would be the target of a Cure Wounds, Mass Cure Wounds, Healing Word, Mass Healing Word, Heal or Mass Heal spell, you do not restore hit points from the effect of those spells. Such spells in fact have no effect on you. If you are the target of an Inflict Wounds, Negative Energy Flood, or Harm spell, you take no damage from such spells, and in fact, you recover hit points equal to the damage those spells would deal to you. 

Additionally, when you choose this sorcerous origin at 1st level, you are able to gain knowledge of spells that are an expression of the malevolence tainting your soul. When you choose a sorcerer spell, you may choose from any of the spells from the following list in addition to the Sorcerer spell list:

1st level- Bane, Inflict Wounds
2nd level- Flaming Sphere, Ray of Enfeeblement
3rd level- Bestow Curse, Vampiric Touch
4th level- Black Tentacles, Phantasmal Killer
5th level- Contagion, Negative Energy Flood
6th level- Harm, Magic Jar
7th level- Simulacrum, Symbol
8th level- Dark Star, Feeblemind
9th level- Imprisonment, Ravenous Void

Corrupted Flesh

1st-level Corrupted Soul feature

At 1st level, when you choose this origin, you are subjected to the internal corruption in your spirit, which has affected your outward appearance, but still yet given you an enhanced form of toughness or otherwise beneficially changed you. When you choose this origin, you gain your choice of one of the following benefits: 
Scaled Skin. You have patches of scaly flesh and toughened, calloused skin. You have an armor class of 13 + your Dexterity modifier when you aren't wearing any armor.
Charred Flesh. You have skin that appears to be burn-scarred in places or simply ashy and charred in some spots. You gain resistance to fire and lightning damage.
Wicked Claws. Your hands have distorted into claws that you can inflict harm with. You grow claws that you are proficient with, and which attack using your choice of your Strength or Dexterity modifier. These claws deal 1d4 + your choice of Strength or Dexterity modifier slashing damage. If you make a melee spell attack as a part of casting a spell and you hit, you may add 1d4 nonmagical slashing damage to the damage of that spell.

Malevolent Mien

6th-level Corrupted Soul feature

At 6th level, you emanate such extraordinary malevolence and corruption that you now are able to exude an aura of dark magical power. As a bonus action, you emit a dark aura, which causes bright light within 10 feet of you to become dim light, and dim light within 10 feet of you to become dark. Creatures of your choice who start their turn within 10 feet of you must make a Wisdom saving throw at your spell save DC or become frightened of you until they are no longer within 10 feet of you. Additionally, while this aura is active, you have a +5 bonus on Charisma (Intimidation) checks and Dexterity (Stealth) checks, but suffer disadvantage on all other Charisma checks. This aura lasts for 1 minute or until you cancel it.

Additionally, you may now spend 2 Sorcery Points to gain darkvision to 60 feet and the ability to see in magical darkness for 1 hour. Your eyes become solidly black throughout whenever you use this feature.

Chilling Vile Blackness

14th-level Corrupted Soul feature

At 14th level, you gain the ability to summon forth a cold and terrible darkness which ushers forth a powerful aspect of the sadistic malevolence inside your soul. You learn and can cast the Darkness spell once without expending a spell slot. When you cast this spell this way, creatures who enter inside or starts their turns inside the radius of the Darkness spell have their speed reduced by 10 until the beginning of their next turn. Furthermore, if any creature starts their turn inside the Darkness, that creature must make a Constitution saving throw at your spell save DC or suffer a level of exhaustion. You may use this feature a number of times equal to your Charisma modifier before you must finish a long rest to use it again, and you may use your Metamagic to change this casting of Darkness as normal for a Sorcerer spell you cast.

Additionally, you learn and can cast the Enervation spell once without expending a spell slot. When you cast this spell, you may use a bonus action or an action on each of your turns to automatically deal 4d8 necrotic damage to the target. If you are concentrating on this spell, you cannot cast other spells that expend spell slots.

Evil's Magics

18th-level Corrupted Soul feature

At 18th level, the horrid power that dwells inside you has been refined by your force of will into a force you can use to reshape your spells in new ways. When you gain this feature, you gain two new Metamagic options: Consumptive Spell and Virulent Spell.
Consumptive Spell: when you cast a spell using this metamagic option, you expend the minimum spell slot required, and you are able to cast the spell as if it were spell levels higher if you choose to have the spell inflict 1d6 force damage to you for each spell level you would choose to improve the spell. This damage to you ignores force resistance and immunity and cannot be reduced in any way. You cannot increase the spell level of any spell beyond the highest level spell slot you can cast. For example, you may cast Fireball with this metamagic option, expending the 3rd level spell slot for that spell, and then you may choose to increase the spell level by three levels, as if it were cast using a 6th level spell slot, and this option deals you 1d6 force damage that cannot be reduced or negated for each additional spell level, for a total of 3d6 force damage.
Virulent Spell: when you cast a spell using this metamagic option, you spend 3 Sorcery Points as you cast the spell, and that spell must have no more than one target and it must force a spell attack roll or a saving throw. If the target of the spell is hit by the spell attack roll or fails the saving throw, you may choose another creature within 30 feet of the target, and that creature also has the spell cast on them at the beginning of their next turn without expending additional spell slots. If that creature is also hit by the spell attack roll or also fails its saving throw, you may choose another creature within 30 feet of that creature to receive the effects of the spell at the beginning of their next turn. As before, you may repeat this process until the spell attack roll misses or a target succeeds at the spell's saving throw or also until you choose no other creature to be the target of the spell. A creature that has already been affected by the spell or by the effect of this metamagic option cannot be targeted again from the same casting of the spell.

Additionally, if you are severely wounded, the evil magic inside you bursts forth unchecked. When you are reduced to 0 hit points, each creature within 15 feet of your body must make a Dexterity saving throw at your spell save DC. Each creature in the area suffers 10d6 cold and necrotic damage and suffers a level of exhaustion, or suffers half as much damage and no exhaustion on a successful save. Effects that would reduce this damage, such as resistance, Evasion, or other similar features do not reduce the damage inflicted by this feature. Only immunity to necrotic or cold damage can negate this damage. You may use this feature once before you must finish a long rest to use it again.