The Physique Tribulation's strength is proportional to the Physique's level. Immortal Physique's tribulation are the strongest and very few people were able to surpass it. For that reason, there are so few Immortal Physique users since the beginning of time. Moreover, the difficulty of the Physique Tribulation increases with the difference between the level of person's current Physique and the cultivated one's. A person with a Mortal Physique who cultivates a Immortal Physique has the most terrifying Physique Tribulation.
The strength of the Physique Tribulation also depends on the level of the Physique Merit Law; cultivators of the supreme Laws from the Physique Scripture has a much more horrifying Physique Tribulation.
The Physique Tribulation manifests itself physically as the Physique Devil (体魔), appearing from a door in the sky. Once a Physique Devil is born, it would devour the cultivator's flesh until nothing remains. Moreover, the Physique Devil is many times stronger than the real user's body, so it is extremely difficult to surpass it.