From Tekken Zaibatsu Wiki
After infiltrating The King of Iron Fist Tournament 5, Raven found Heihachi, who many believed was dead, and engaged him in combat. Before the fight ended, Raven was ordered back to headquarters and retreated.
As the world was trying to recover from the devious work of the Mishima Zaibatsu, the conflict between that organization and the G Corporation escalated. It appeared to be only a matter of time before this discord turned into a large-scale encounter. Raven infiltrated The King of Iron Fist Tournament 6 in order to stop further carnage.