Lich Lord of the Witch Wood

Hypnotic suggestions from being mind controlled persist after the controller’s death, causing the victim to occasionally take actions to support the cause of a mind flayer cult that no longer exists.

Repeated demonic possession has left the patient with permanent gaps in their soul’s defenses, causing them to immediately get re-possessed if they go outside a consecrated area.

Post-resurrection trauma as the revived soul remembers an unpleasant afterlife.

Curse of bad luck - makes any small illness or injury potentially fatal if not treated with anti-curse in addition to anti-infection procedures

Magical reliance on a magical or nonmagical substance - can have any number of side effects

Repeatedly being drunk by vampires can cause an increase in blood production and therefore high blood pressure and related ailments. Can be treated by blood letting.

There’s a lot of hybridization happening in a lot of fantasy settings, and that’s just asking for a lot of people with weird half-dragon genetic disorders. Works out fine for some people, not so much for others.

Parasitized by (insert creature here). If you don’t take the correct precautions to keep it dormant it will continue to spread and eventually hatch out/transform you.

Repeated contact with the undead has left you open to their influence - leading to hearing or seeing things that other mortals can’t, which can distort or distract from more mundane concerns.

Alternately to being more vulnerable to intrusion, one’s soul can form a scar that makes helpful magic more difficult to take in.

Sleep disorders that make one fall into an impenetrable sleep at a specific trigger, or to do so for years at a time.

Out of phase with 4D space, one’s body not connected to itself or anchored in place/time in the usual way. There could be a consistent two hour gap between the things you hear and what has happened, you might clip into the floor as if it was in a different place for you, or you might slide through the material plane in cross section.

Intermittent intangibility.

Split into two people, each with only half your traits.

the forgotten dread: memory modification magic has caused the subject’s conscious mind to forget some past trauma, but their subconscious still remembers, causing them emotions that they cannot explain or justify ranging from mild discomfort to blind panic when presented with triggers related to the aforementioned trauma. often encountered in cases where the subject has paid an unscrupulous mage to make them forget their past as an ill-advised alternative to therapy.

Psychically Transmitted Memories: the subject’s mind has been linked to another person’s and, although the bond has since been severed, they have retained memories or thought patterns from the other person that are difficult to distinguish from their own.

Negative Life Syndrome (previously “False Life Syndrome”): seen most often in cases when the subject is exposed to dark magic while in the womb, Negative Life Syndrome leaves the subject’s life energies tainted by undeath without making them truly undead. common symptoms include intolerance of radiant magic, aversion to sunlight, and the inability to set foot on hallowed ground; rare symptoms include healing from negative energies, sudden necrosis, and the desire to eat flesh or drink blood of living beings.

lycanthropy

Awareness of too many dimensions makes it difficult to interact with just this one - either to keep track of conversations, or walk to specific locations without ending up on another planet instead

Telekinetic psychosis - delusions tend to physically affect those around you (but HIGH chance for ableism in this one!)

you have flare-ups where your skin tends to slough off and be replaced by some other substance

After sharing life energy with a dying loved one, you’re now both trying to survive off one person’s supply. Like chronic fatigue, but if your loved one gets too big of a bruise you won’t have the energy to get up until it heals

living in reverse

stuck at a certain age

supersenses lead to constant overstimulation