[Coldsaturn]

What I incredibly like about him as a LI compared to the other LIs is that across the main chapters you might catch hints at the fact that he's not-so-silently pissed off at MC. Like, genuine mistrust and holding a grudge. But he still approaches her and gets into this sexually charged push&pull with her, which might just be making him even moodier.

That is wonderful. Fantastic even. Thanks for the insight here, I was (obviously) not getting that at all from my interactions with the man so far; its all been quippy and slightly off center and not exactly grounded in reality (which is probably why I'm preferring Zayne the most out of the original three).

I pulled one of his 5 star cards (Deep Sea Promise I think it was called) where the accompanying mini-story was that HE was the bodyguard and I was the princess which I thought was pretty cool. I should go back and watch that again with new knowledge in mind.

Deep Sea Promise my beloved <3 That is one of his myths! Not a limited myth, since you can pull the card regularly outside of his limited events, but a myth nonetheless. Is it a past or future timeline? We are 30000 years after the seas dried up. I'll leave you to your theories.

In the first half of the main story you get his diva persona, but as you said there are some "??" moments. He's full of contradicting signals. But let's remember that when we meet him the first time, he literally walks away while we're still talking. Then there's that moment where he sees us drowning and legitimately turns away (several fan theories justifying this moment and I'm here like "no you don't understand, I'd LOVE it if he actually meant to let MC die there") until we say "Don't go" triggering that symbol on his chest, after which he saves us. And you'll see how things will evolve in the second half of the main story. Then there are some other strong clues in his anecdotes and cards and tender moments. 
I will die on this hill: pre-love story Raf so desperately wants to tell MC to go fuck herself but is being cockblocked by the writers.