Devils

Devils were a lawful evil race of fiends who hailed from the Nine Hells. Devils were vicious creatures who were capable of attacking and killing others for essentially no reason. However, they hated being the target of misery themselves. This led to another trait of devils, their extreme vindictiveness combined with a lack of ability to accept their mistakes. Devils had an instinct to look for others to blame when they suffered setbacks and had the drive to exact vengeance against whomever they held responsible, even when they were demoted to a weaker station. For example, the grandson or granddaughter of a dead being who was indirectly involved in the demotion of devil was an eligible target for the demoted devil, even after it managed to be re-promoted. Devils often delegated their work to others. This did not mean that they were lazy, however, as the primary personality trait for any devil was ambition. They constantly looked for ways for promotion. The goal behind this behavior was the fulfillment of the devil's own desires. They tried to rise up the hierarchy to modify rules in ways that suited them. This was the root of their dedication to the cause of lawful evil.
These fiends had some tendency to act on emotion, especially when faced with the prospect of vengeance, and with enough provocation, could be made to act in ways that were detrimental to their ultimate goal, up to death in pursuit of such vengeance.