Otherworldly Patron - Nosomatic Chirurgeon

Those of House Jorasco are known far and wide for their understanding of life, and their facility to care for the injured and dying. It is no surprise therefore that as much as they are known for their knowledge of life, they must also understand death, and some who are exposed to a lifetime of death and madness pay a price.

Within Jorasco are a militant sect of healers who twist their powers to darkness; though not uniformly evil the powers they wield is a dark stain on Jorasco's reputation, and when discovered it is frequently an agent of Jorasco who is first sent to silence a Nosomatic Chrurgeon.

Those who ply their trade either do so secretly from within the house, or are sometimes excoriates and viewed as aberrant. Many whisper that they risk a return of the Lady of Plagues. Whether bookish or more hands-on, these disease-affiliated physicians often maintain a stoic level of detachment from their work, and frequently cultivate skills of deception or misdirection to avoid discovery. When pushed to enter the fray, they are usually merciless to their enemies, while remaining observant of the effects of their magic. Their hunger for knowledge is a defining trait, just as with many other warlocks.

In order to take this subclass, you must be a halfling with a Mark of Healing. Your dragonmark itself becomes your patron.

Nosomatic Chirurgy

Your understanding of sickness and disease grants you a certain amount of protection against them. You have advantage on saving throws against being poisoned or diseases, be they magical or mundane. This affiliation with such maladies also gives you an air that seems to make creatures less eager to strike you. While wearing no or light armour, your armour class is increased by +1. This bonus increases to +2 when you reach 11th level in this class.

Finally, instead of using Charisma as your spellcasting ability score, you use Intelligence instead. Likewise any invocations or features that rely on Charisma (such as Agonising Blast) have this changed to Intelligence.

Pestilential Touch

Your very touch seems to sap the strength from a target. From 1st level whenever you cast a warlock spell that has a ranged attack roll, you can instead change it to a melee attack roll with a range of 5ft. Once per turn when you cast a spell against a creature that is adjacent to you, and you either hit with the attack roll or the target fails the saving throw you may deal an additional 1d8 poison damage to the target.

Plague Bearer

Your knowledge of diseases is supernatural due to your dragonmark, allowing you to retain not just knowledge but also the essence of disease. When you observe a creature that either suffers from or applies a disease (such as a Mummy) you may use your bonus action to make a Medicine ability check with a DC equal to the diseases save DC. On a success, you add that disease to your knowledge base. If you fail, you cannot attempt the check again for at least 24 hours.

As an action on your turn you can attempt to infect another creature with a disease you have successfully learned by touching them. Instead of the disease's normal save DC, it now uses your spell save DC. Concealing the attempt at infection requires a successful Sleight of Hand check against any observer's passive perception.

You may only attempt to infect another creature a number of times equal to your proficiency bonus, refreshing on a long rest.

Finally, your magic prevents you from being infected yourself, granting you immunity to all diseases.

Nosomatic Touch

From 10th level you learn to combine your Pestilential Touch and Plague Bearer features. Whenever you deal damage with your Pestilential Touch feature, you can expend a use of Plague Bearer at no additional action cost to attempt to infect the target of your spell.

In addition, your Pestiliential Touch damage now bypasses Immunity to poison damage, treating it instead as Resistance.

Ascendant Carrier

By reaching 14th level you diversify your portfolio of protection, gaining resistance to poison and necrotic damage.

In addition, your diseases are so potent and virulent that even those normally immune to disease are now able to contract and suffer from your infections - your diseases bypass immunity, the magic of your dragonmark allowing them to work even against those who might not normally have a body capable of feeling such afflictions (such as the undead).