Nosomancer (Cancer Mage)

2024 version of the iconic 3.5 ''Cancer Mage'' class, reimagined as a Wizard subclass.

Shunned by society for their foul nature and abilities, nosomancers are wizards and scholars specialized and fascinated by the effect and manipulation of worldly diseases. A nosomancer usually embraces any and all diseases and ailments that comes their way, seeing it as a potential for growth. Therefore, they are seen by most as utterly repulsive for their sickly appearances and philosophies, often being left to live on the fringes of society, if not outright in exile from larger communities. Nosomancers are primarily evil beings, likely to use their unsightly powers for malicious, cruel intent. There may be, however, a rare few among them that use their studies of diseases to aid the sick and needy.

Level 3: Plague Savant

You gain resistance to poison damage, as well as immunity to the poisoned condition and to any ill or contagious effects from diseases.

Additionally, you add the Detect Poison and Disease spell and one other spell from any spell list to your spellbook for free, the chosen spell must deal poison damage or inflict the poisoned condition.

Whenever you gain access to a new level of spell slots in this class, you can add one spell with the same restrictions to your spellbook for free. The chosen spell must be of a level for which you have spell slots.

Level 3: Infectious Spells

When you cast a Wizard spell on your turn that deals damage to one or more creatures, choose a number of affected creatures up to your Intelligence modifier, roll 1d6 for each of them and add the roll's total together. You may deal additional poison damage equal to the total, divided as you choose among the targets.

Level 6: Viral Agent

When you finish a long rest, you can develop a sentient disease within your body. While you host the disease and don't have the incapacitated condition, it will warn your body of imminent danger, granting you a +2 bonus to your AC and Dexterity saving throws against effects you can see.

Whenever you touch a creature or affect it with a Wizard spell, you can subtly transfer the disease to the target as a virus. While the target hosts the virus, you can detect the target's location from any distance, as long as you are both on the same plane, as well as see and hear from their perspective while they are within 1 mile of you. You can choose if the virus will reproduce the effects of any mundane disease (your choice), including whether or not it is contagious, or if it will remain dormant and undetectable. If a creature hosting the virus has it cured through any means, the virus and the sentient disease will vanish.

You can only have one existing sentient disease at a time, and it will vanish if you try to create another one, or if you die.

Level 10: Epidemic Spells

You gain immunity to poison damage, and the damage from your Wizard spells and from your Infectious Spells feature ignores resistance and immunity to poison damage.

Additionally, whenever you use your Infectious Spells feature, you can target two additional creatures, potentially adding to the roll's total damage.

Level 14: Disease Form

You make your body into a powerful disease. As a Magic action, for 1 minute, you, along with anything you are wearing or carrying, become a cloud of an airborne pathogen, replicating on yourself the effects of the Gaseous Form spell, except you are invisible and have a fly speed equal to your speed for the duration.

While in this form, if you end your turn on the same space as another creature, you may attempt to enter its body and infect it. The target must succeed on a Charisma saving throw or be infected. The target has disadvantage on the save if you have dealt poison damage to it or poisoned it in the last minute, or if it is diseased. While infecting the target, you share its perspective and space, and you control it, acting and moving as if you were the creature. You can't be targeted or affected by anything that would also affect the target. At the start of each of its turns, the creature repeats the save, ending the effect on itself on a success, otherwise it doesn't move or take actions during its turn. If the target succeeds on the save or when the effect ends for a target, the target is immune to this effect for 24 hours. Undead, constructs, oozes and plants are immune to this feature.

Once you have used this feature, you can't use it again until you finish a long rest.