Heihachi because Reina seems to be very loyal for him. Heihachi may either turn out to be an asshole and do it for no good reason or not to share the winnings with anyone or he will simply be afraid of Devil Gene.
@Oda1271 yeah Heihachi will use and betray her just like he did with Jin and just like he tried to do with Lars except Lars could see through his bullshit
