I think the main problem about the Noctis x Luna chunk of the story is not even the fact that their lovestory is told poorly but the fact that their relationship is
labeled as a lovestory... Which is fundamentally different from what the story actually shows. We have two kids who spend some time together and then basically just message each other with stickers and cryptic captions via a magic dog for years. I seriously doubt that people can develop a healthy and plausible romantic relationship in these circumstances. Remember her post mortem dream sequence? While she's saying goodbye, Noctis sees himself as a child who is swimming towards mature present day Luna. A child, mind you. I assume Noctis treats Luna as a sort of an older sister figure or a very special friend at best. Meanwhile Luna is probably eager to get married not only out of her preordained role as an Oracle but also out of curiosity, because life's no longer going to be boring and repetitive. And I imagine essentially it's like befriending your old friend again, because God knows long-distance relationship never really work.
The best chemistry in the game?
Gladio and Cup Noodles
Cindy and Regalia
PROMPTIS
Prompto is hands down my favourite thing in the FFXV universe. I didn't even think it would be him, but I realised that on the very first day of my playthrough. The moment he appeared in the tutorial to aid Noct in battle, he slipped and slid right in front of him, and I knew at once that we would get on well. The moment he sang the victory fanfare, he stole my heart without a sweat. And the moment he was about to shit his pants in fear when the party was crawling near a gigantic bird, I realised I absolutely needed him in my life. And then that heart-to-heart talk on the rooftop. His silly selfies and self-indulgent photo ops. His lovesickness. His origins. And his special bond with Noctis.
Before I started the game, I thought it was quite refreshing to have 4 main characters with semi-friendly semi-brotherly bonds with very low shipping potential so people would naturally ship them as they please relying on their power of imagination and preferences alone, but I was wrong, I was oh so wrong. It may or may not be inherently romantic, but Noctis and Prompto's chemistry is so palpable that you don't even have to dig for evidence. It's right there. Unlike Gladdy Daddy who still remains a rough and tough kingly mentor, and unlike Mama Ignis who still takes care of the prince in and out of battle, Prompto starts off as his classmate. They are completely on the same page despite Prompto's insecurities. They have unique in-game interactions like high fives, bro handshakes, ass slaps, Noctis catching his pal's fall after a particularly strong chain attack etc. While on the road, Prompto is always looking back over his shoulder or dangerously bending over his own seat to chat with the others like a bee around a honey pot. This animation is never triggered when Noctis is behind the wheel. Noct often smiles when Prompto sings or sums up the results of the battle or just says something particularly silly. He is well aware that his pal is a pleb, but maybe that's the biggest reason he feels most comfortable around him: they spend a lot of time together, and Noctis can forget about his burdens for a minute in Prompto's company. And he knows he won't be judged or reminded about his duties, so he can relax and have a good time for a change. Meanwhile, Prompto has someone to look up to, someone he adores for a number of reasons, someone who provided him with the craziest adventures he could ever imagine. If this is not a perfect friendship, then I don't know. Prompto resonates with me a lot, and I ship them in the most platonic way because I want them to be happy and enjoy travelling together just a little more before things go awry.
I was also amazed to find out that Noctis and Prompto's VAs, Ray Chase and Robbie Daymond, are best friends in real life, they regularly stream games together with Max Mittelman (Red XIII/Tredd Furia VA) on their Twitch channel
LoudAnnoying, and they replay FFXV every now and then often reenacting certain scenes or just having fun with the mods. How cool is that?