(spoilers for the manga, LN, WN you name it)
Jinshi or rather Zuigetsu is such an interesting character for me because of the dichotomy. We're initially introduced to him as someone with a lot of pride in his looks, confident, mature beyond his years. Later on, we find that his true self is quite self-depreciating and childish.
He doesn't have an attachment to power, nor his looks. He's actually not the arrogant lord Maomao initially thinks he is because he's open to learning and taking the advice of those who know more than him. And while this feeds into his complex that he's surrounded by eccentrics who are extraordinarily good and excel at one thing (the entire Ra Clan, Maomao included, Basen etc.) he's no slouch himself!
I mean Jinshi doesn't think much of himself considering himself a jack of all trades, but what a wide variety of trades it is - he can beat Basen using skill instead of force, he beat the Emperor at Go at the tender age of fourteen and this is with the Emperor having been taught by the Sage who is one of the only two people known to have beat Rakan, he dances with such grace that foreign envoys can only think of him as a goddess, he's enough of a quick study with medicine according to Maomao, not to mention his prowess at both the military arts and diplomacy.
As if to make up for all that he perceives he lacks, he knows talent when he sees it and will use people accordingly. Ironically (and though they would both hate to hear it) Jinshi and Rakan are more than a lot alike. Despite his complex, these qualities actually make him quite a good leader and you could see why the Emperor really wants to make him the Crown Prince even if this isn't Jinshi's wish.
But unlike Rakan, he is still soft-hearted at his core (see the case with Fuyou for example). And though Maomao is rankled at how he attempts to be both pragmatic and kind, at his inability to wholly abandon his heart for the things he knows must be done, at her core, I think that trait of Jinshi's is the main reason why Maomao finds herself unexpectedly loyal to him.
Much has been said for Maomao's charisma, but Jinshi also attracts loyalty from unexpected places. Like Gyokuyou, he surrounds himself with capable people. While part of me is cheering him on to get his wish of being an ordinary person, I feel like everything has been building up to his eventual ascension to the throne. Because while Jinshi may complain and grumble about his work, ultimately he will still do it. At present, he could only implement his plan because he still thinks he's just the Imperial Brother. But the moment the truth gets revealed, he won't easily be able to shake off his burden.
A part of me thinks that he will eventually take the throne in some form or the other, but only until Gyokuyou's son comes of age and he can finally pass on the crown and become an ordinary person once and for all. This scenario would actually be the perfect pretext for him to justify having only Maomao for his sole consort since he can reason out that he doesn't want to further complicate the lines of succession by having more children with more consorts. In other words, a win-win possibly for both Jinshi and the current Emperor (except Maomao haha).