New Sorcerous Origin

Tainted Blood

Your innate magic is drawn from the Corruption that flows through your veins. Whether it stems from a long forgotten pact, from the grafted-on organs of fallen magical foes or an ancient curse; you can take this dark power and bend it to your will, for a price...

Aberrant Lineage

At 1st level, while you have atleast one Corruption level, you gain the ability to telepathically communicate single word ideas or a mental image of an individual, to another creature you can see within 30ft. You can use this multiple times to communicate more complex ideas but if they cannot be summarised in 3 words or images, it will take 10 times longer to express than speaking. They do not need to share your language to receive the message though they may not understand. In addition, you gain 60ft darkvision if you do not have it already.

Corruption

At the 1st level, you gain access to corrupting magic. Corruption acts just like Exhaustion except it cannot be removed by any other means, save resting and special events at the DM’s discretion (such as a Cleric’s Divine Intervention or the Wish spell). It also stacks with any existing exhaustion and after each long rest you can only ever gain up to your proficiency’s worth of Corruption (you may end up with more though, from previously existing Corruption).

Corrupted Spells

At the 1st level, you may gain a level of Corruption as a bonus action in exchange for casting more powerful spells. For the next minute, when you cast a sorcerer spell, you may use the next size larger damage dice rather than the usual dice up to a d12. For example, when casting Fireball, you may deal 8d8 damage rather than the usual 8d6.

Corrupted Nature

At the 6th level, you gain resistance to necrotic damage.

Additionally, during a short rest you can spend 4 sorcery points to remove a level of corruption.

Finally, when a target would suffer no damage from your Corrupted Spells (potentially due to Evasion or Damage Type Immunity), they instead suffer half.

Corrupted Arcana

At 14th level, you gain the ability to spread the Corruption amongst your foes. As an action you may transfer corruption to your foes. You may gain a level of Corruption so that you can target a creature you can see within 60ft and force it to make a Wisdom saving throw. If it fails it gains 3 Corruption Levels. If it succeeds, instead it gains 1 Corruption Level. A foe can never gain more than 3 Corruption levels, through this ability. This lasts for a minute.

In addition, as a reaction when targeted by a spell, you can use the corruptive magic to boost your arcane resilience. You may gain a point of Corruption, so that you gain advantage on any spell saves and gain resistance against the damage of the spell.

Twisted Life

At the 18th Level, when you would have 6 Levels of Corruption, you undergo a terrible transformation instead of dying. Your skin turns a dark shade, with tentacles errupting from your body. Your eyes begin to glow with alien intent as the Corruption finally takes hold...

Instead of gaining your 6th level of Corruption, for the next minute gain immunity to exhaustion and Corruption, you cannot use any abilities which would grant you more Corruption and gain temporary hit points equal to your missing health which last until the end of the transformation. You lose all levels of corruption once the transformation ends. In addition, your creature type changes to Aberration, until your next long rest. Once you use this feature, you cannot use it again until you finish a long rest.

Acknowledgements Special thanks to IrishBandit, RockGoliath, MarcSharma and ArtoriusaurusRex for their advice and byartofcarmen for this picture. If you wish me to take it down contact me. Thanks also to the works of Studio Ghibli, Jim Butcher with his Dresden Files series and other similar works for inspiring this.