The TEKKEN 7 Ending to the Mishima Saga pits Heihachi and Kazuya against each other for the final time. The setting — where else but at the seat of an active volcano. Heihachi seems to be able to hold his own but Kazuya activates his Devil form and that proves to be too much for the old man. I can’t think of any other way for Heihachi to go out.
TEKKEN 7 ends the Mishima Saga with a final battle between father and son: Heihachi and Kazuya.
The Mishima Saga doesn’t quite end here, though: a Special Chapter is revealed where Akuma is prepared to be Kazuya’s next opponent. The Mishima Saga also ends with Devil Jin preparing himself to take on Kazuya himself.