Devil is one of the main antagonists in the Tekken fighting game series. He made his debut in Tekken. He is a devil form/true form of Kazuya Mishima. He was also known as Devil Kazuya. He is a father of Devil Jin through the devil gene. Devil split from Kazuya after he was nearly killed at the end of The King of Iron Fist Tournament 2. In Tekken 7 it is revealed that Kazuya inherited the Devil Gene from his mother Kazumi Mishima at birth. A scene in the opening of Tekken 3, portraying a ghostly figure branding the arm of Jin with a mysterious tattoo that leads many fans to theorize that Devil would later possess the body of Jin, after the disappearance of his mother, Jun Kazama who had protected her unborn child from it 15 years ago. However Jin inherited the Devil Gene from his father at birth.
Devil is a power-hungry, unforgiving entity who is motivated by power above all else, and enjoys causing pain to other people, suggesting a sadistic nature as well. He displays no remorse for the damage that he causes to others in his quest for absolute power and control over the world. He is also extremely arrogant, as he believes that his power is unmatchable. He appears to be very cunning and is ruthless in battle. He also very manipulative, such as attempting to lure others who are cursed by an evil entity like Jin to succumb to its power through merciless fear and pain, in attempt to gain theirs as his own.
After being thrown into a mountain ravine by his father, Heihachi Mishima, Kazuya Mishima gained a evil energy known as "Devil Gene" witch made him extremely powerfull. Kazuya, driven by anger and hatred entered the tournament to kill his father, Heihachi. The power of Devil allowed Kazuya to finally defeat Heihachi in the final round in Tekken.
Since Kazuya met Jun Kazama, another entity was created within Kazuya known as Angel which represented all that was good within him.
Kazuya announced the King of Iron Fist Tournament 2 in Tekken 2, Heihachi Mishima beats Kazuya and the Devil Gene inside him causes transforms into Devil. Devil is stilled defeated by Heihachi, He was thrown into a volcano.
In Kazuya's ending of Tekken 4, Devil consumes him when he goes with his father and see his son and enemy, Jin Kazama; So Kazuya dislikes the devil gene by inside Jin. Jin beats Kazuya easily and his grandfather, Heihachi. He transforms into Devil Jin almost kills Heihachi and his mother Jun Kazama stops him. Devil Jin flies away.
In Tekken 5, Kazuya and Heihachi fights some of Jack-5s. Later, Kazuya transformed as Devil flies away.
Project X Zone 2
Devil will appear in the upcoming sequel to Project X Zone as a transformation for Kazuya.
Namco X Capcom
Devil Kazuya makes an appearance as a boss in Namco X Capcom.