Devil

Devils, also known as fallen angel, are malevolent beings of all existence. They are often associated with The twelve infernal pits , a plane of existence ruled by powerful archdevils. Devils are cunning and manipulative, using their intelligence and charisma to corrupt mortals and turn them to evil. Devils come in many different forms. They are known for their red skin, horns, and sharp claws, as well as their ability to wield powerful magic. Many devils have wings, allowing them to fly and maneuver through the air with ease.
Devils are known for their deceitful nature and their ability to trick mortals into making deals that ultimately benefit the devil more than the mortal. They often disguise themselves as charming, charismatic individuals, promising wealth, power, or knowledge in exchange for a favor or service. However, these deals often come with hidden clauses or consequences that the mortal is unaware of. One common tactic of devils is to present the mortal with a seemingly simple task or request, but as the mortal completes the task, the devil reveals that they have unknowingly entered into a binding contract with the devil, with severe consequences if the mortal does not uphold their end of the deal. Devils may also manipulate mortals into making decisions that they would not normally make, such as choosing between two equally terrible outcomes, by presenting the choice as a test of the mortal's loyalty or character.
Devils are also known for their ability to twist the truth, often presenting half-truths or outright lies in order to manipulate mortals into making deals or following their orders. They may use illusions or other forms of magic to deceive mortals or hide their true nature. Some devils are even capable of possessing mortals, taking over their bodies and using them to carry out their own sinister plans. However an important features of them is that they can not lie. 
According to the lore of the devils, the inability to lie is a fundamental law of their existence, which is often referred to as the "Pact of Veracity" It is said that when Kor, the archdevil of the twelve infernal pits, first rose to power, he faced many threats from his own kind who wished to overthrow him and take his place. To protect himself from such threats, Kor decreed that all devils who wished to serve him must abide by the Pact of Veracity, which states that they cannot lie under any circumstances. Kor bound all other devils which serve him and thus only Kor and all devils not following Kor are not bound by this pact.
Despite their deceptive nature, devils are not without their own code of honor and hierarchy. The most powerful devils hold positions of great authority in The twelve infernal pits , while weaker devils serve them in exchange for power and protection. They often operate under a strict set of rules and are loyal to their own kind. They may form alliances with other devils or even mortals if it serves their own interests, but ultimately, their main goal is to gain power and influence over the mortal world.

Devils are often seen as the antithesis of celestial beings, such as angels and archons. While celestials represent all that is good and just, devils are embodiments of evil and corruption. They are constantly at odds with one another, with each side seeking to gain an advantage in the eternal struggle between good and evil.