^ Yes, I believe that's the case
She likes Ganryu not romantically but merely because he reminds her of her father.
I believe devil gene only enhances their strength when Jin and Kazuya transformed, though. Heihachi doesn't have it yet he managed to defeat Kazuya twice while Kazuya only won against him once. Not to mention he also supernaturally survived numerous explosions
So I believe the strength of Mishima clan stems from their bloodline.
