Well, I have a concept actually! But it's just not an easy concept to fit in... the majority of roleplays, I think. Much like Rayen, you have to know what you're doing, basically.
To break it down: this would be a character that, by personality, just isn't that easy to throw into new situations or to approach in general. And I've found it a bit harder to make the development of this kind of characters feel natural and to make them seem believable, compared to someone like Arianne who is mostly expansive and eager to make friends. Plus, I as a writer still have to improve with relating to characters that are very different than me. So, the personal aspect is something to consider here.
It's also true that this character, the way I've been thinking about them, well... it only fits a certain kind of background and setting. It probably works better in roleplays that have a generally darker tone, something that keeps the focus on their personality traits and their struggles. And that also means making sure the roleplay in question lets you participate with characters of a certain age.
Trying not to make too many spoilers... there are some not really nice parts of me that I would like to bring on the surface with a character like this, and I'm hopeful that if done right, this might be even cathartic! But adapting that core concept to different situations, depending on which roleplays are open to join, is not that easy! I might even add in the schedule problem, and how I should be careful not to start too many commitments... but I'm not even sure that's the main thing that's making me put these ideas on the backburner. The fact is, though, that's where this character is gonna stay for the time being~