Kazuya Mishima

Kazuya Mishima is a character in Tekken and has been in every game except Tekken 3, when he was presumed dead. Kazuya Mishima is the son of Heihachi Mishima and Kazumi Mishima, of which the ladder died early on. He is the grandson of Jinpachi Mishima and the father of Jin Kazama due to an unexplained relationship with Jun Kazama. He is has a half-brother named Lars Alexandersson who he had been unaware of much of his life, finding out about him in the King of Iron Fist 6. Lee Chaolan is his adopted brother who Kazuya never liked and shared an intense rivalry with.
When Kazuya's name is written in Japanese, it's translated as 三島 一八(Mishima Kazuya) or みしま かずや(Mishima Kazuya). Kazuya gets 八(hachi or pachi or ya) from 平八(Heihachi) and followed 一(ichi or kazu) which means a beginning because he is the eldest son. The notation that 一八 is rare in Japan.
In the original entry to the Tekken franchise, Kazuya was considered to be the primary protagonist. And for all intents and purposes, there was no reason to believe differently. According to differing sources (such as Tekken: The Motion Picture and a brief scene in Ling Xiaoyu's Tekken 5 ending), Kazuya was actually quite frail, kind and timid as a boy and was the victim of years of abuse at the hands of Heihachi. Indeed, Kazuya originally entered the first Rave War/King of Iron Fist Tournament in order to face off against his father, who was played up to be a corrupt corporate tyrant. Kazuya's clothing of choice is simple white pants, red gloves and footpads. There was only one clue as to Kazuya's true intents and nature: His secret PS One palette swap, which turned out to be Devil.
Tekken 2 saw Kazuya's true nature revealed in full. After he believed his father was dead, instead of bringing justice to the Mishima Zaibatsu and righting the wrongs of his father, Kazuya repeated the corrupt practices of his father and turned it into an even more ruthless organization. While Heihachi was merely ruthless, Kazuya acted absolutely without a conscience. He hired assassins to eliminate any of his critics or rivals (such as the father of Eddy Gordo), he attempted to extort money from several businesses and organizations, and he even smuggled endangered species and conducted genetic experiments on them (Alex and Roger).
Of course, the reason for his evil deeds was because of the Devil Gene and had allowed his hatred for Heihachi to consume him. Angel, an unknown entity, constantly battled with Devil to determine the actions of Kazuya. Heihachi managed to take advantage of his son's battle of personalities and defeated him in the second King of Iron First Tournament. Kazuya was then thrown into a volcano and nearly killed while the Devil in his body escaped and eventually made contact with Kazuya's son, Jin Kazama, who succeeded his father as the series' new protagonist for the time being.
Before his downfall, Kazuya was protected by Bruce Irvin, Ganryu, and Anna Williams. He was also an assassination target for Nina Williams. He also became attracted to Jun Kazama; he said in his own words "she was so mysterious". This attraction lead to the birth of his only son, Jin Kazama.
Since his original appearance, Kazuya's character has gone through many transformations: from hero, to villain, to anti-hero and back again. Whatever was left of his good side appears to be totally suppressed by his Devil persona. Kazuya no longer fights against his darker side and the two seem to have come to mutual terms, as Kazuya can transform into Devil when he chooses (such as in the Tekken 5 introduction). This is one of the main factors that makes him well known amongst Tekken fans.
His title in the original trilogy is Cold Blooded Leader.


 KAZUYA VS JIN KAZAMA:
https://www.youtube.com/watch?v=A8k_mFMh2ic