Shieeet, I'm turning into one of those casual phegs thinking about how the storyline is gonna play out. What if moms/Hei discovered the devil in moms, and she made Heihachi promise to murk her if the devil got out of control. That temple where she was chilling was probably when the devil went batshit and Heihachi had to put a stop to it. With a little bit of retconning, they can use this angle to explain why he threw Kazuya off the cliff and why he shot Jin point blank in the head: the devil that possessed Kazumi manifested itself in Kazuya, and again in Jin, meaning Heihachi had to bite the bullet and kill his son and grandson too, to end the devil. That would make Hei the tragic hero type. That's probably the best direction they can go with Hei--he's too likable by the Tekken fanbase now to be labeled as a pure evil villain (he's done a shit ton of good things as well that many people seem to forget, not to mention some "good" characters are very close to him--Xiaoyu calls him grandpa and Kuma has stuck with him all this time). Jin and Kazuya's phaggot asses are a lot more unlikable than Hei at this point.