Wyrm Empress's Clench

Overuse of Vanorax combat drugs can leave users changed in permanent ways.

Causes

Wyrm Empress's Clench (or just "The Clench") is caused by prolonged exposure to a combat drug called "wyrm's bile" that Vanorax gives to non-dragonborn troops. It's made from powdered dragon scales, pitgran, and some other alchemical reagents. Using the drug gives the user pain resistance, increased strength, and increases aggressiveness. It's much like a barbarian's rage in powder form.
Using the drug over a long period of time can cause The Clench.

Symptoms

The symptoms of The Clench are progressive and magical in nature. A sufferer initially starts developing a stooped posture and a curved spine, creating a hunched posture. Continued use eventually causes mutations that change the sufferer's musculature into more serpentine patterns, particularly their abdominal muscles. The tightness never really releases, though, hence the name. Advanced cases can be crippling.

Treatment

There are several treatment plans.
The first and most humane is magical in nature. A greater restoration or heal spell will end the effects of The Clench on someone who is suffering from it. This is high-level magic, however, and is not always available.
The second is to get the patient off of wyrm's bile and onto a treatment of healing herbs. This takes longer and once mutation has occurred, will be of limited benefit, but it relieves some of the lasting discomfort of permanently contracted muscles. This type of treatment can, if administered at just the right time, leave a patient more limber and flexible than they once were.
Finally, there are additional substances and magical rituals known to the Vanorax empire that can use The Clench as a starting point for a transformation into a more serpentine entity. A lot of the Wyrm Empress's more snakelike humanoid servitors originally started out as Clench patients.