I'm glad to hear you like Lune! He's been very interesting to plan out so far.
As for which he'd choose, love or his kingdom:
Lune prides himself on always putting duty first, BUT he's never been in love before, so who knows? Maybe he'd surprise himself ;)
Lune's got a lot of dealbreakers. He's not the best communicator, he prefers to keep his emotions bottled up rather than expressing them, and his 'honesty' can sound a lot like rudeness.