My delulu Nishiki head canons are:
He loved Reina then he became obsessed with Yumi due to his desire to be as similar to Kiryu as possible.
I do not believe that he killed Reina personally. It’s super out of rgg’s character to not even show a flashback of the supposed murderer take out their victim. (They even made it clear in yakuza 3 that Mine did not kill Kanda personally, though he is capable.) Tbh it was probably one of his subordinates, but at this point Nishiki is so absorbed in his ego that what his men do is what he’s done. Also, he doesn’t ever kill anyone who made him feel bad. Shimano, Kazama, Kashiwagi.
Nishiki doesn’t approach Kiryu not only because he knows he’ll lose the fight, but because he can’t retain his composure. Nishiki wants to be the mysterious playboy, as said in Y0, however this is quickly disproven when we actually go to Serena and meet Reina cause she tells us how Nishiki pours his heart out to her. The Serena scene in Kiwami is perfectly orchestrated, his words are precise.
His career of choice might’ve pivoted into entertainment. When I see everybody’s hc’s for him they rightfully say he would’ve been a designer, but given what I saw become of the people in Haruka’s circle I’d say Nishiki would’ve fit right in. Actually kind of sad to think about. Maybe if he was Haruka’s talent manager, maybe she wouldn’t be so disconnected from home…
Saejima wouldn’t get along with him at first and vice versa. This is based off of multiple reasons, but mainly because I think of them as a scale and Nishiki and Saejima are just too far apart to immediately click. Do I think Saejima would raise a heated fist first? No. Do I think Nishiki would crack underneath his own pressure? Absolutely.
