A lot of them are at least kind of a mess. I've got semi-disasters, full-blown disasters, people who like causing disasters but aren't necessarily disasters themselves, people who pretend they have it all together but really don't, people who are just kinda lost, etc. But I'm going to try to narrow this down to the most consistently chaotic.
"Irresponsibility" would be Maxy's middle name if he had one, with "bad judgement" being a strong runner-up. He has many ideas floating around in that fluffy hair of his, it's just that all of them land either himself or everyone around him into trouble. He's the one who most outwardly looks like a mess, but in actuality, out of all of my OCs, he's only kind of a disaster. For the most part, he enjoys being this way!
Angelo has many worries, and these worries drive him to do things someone as easily frightened as him would never do. Things that most people wouldn't do. Things like breaking into the military. He doesn't seem the type, but he's very reckless. This newfound recklessness is an attempt to overcome his fears, because he's afraid of causing trouble for other people. Ironically, this causes the most trouble for everyone.
Then there's Mai, who has no sense of self-preservation because she thinks she's built different. Her parents had her to vicariously live through as a power fantasy at the cost of her wellbeing. This backfired because as it turns out, convincing her that she was inherently better than everyone else included them, too. This resulted in someone who has zero self-awareness while being brilliant, talented, athletic, and charismatic enough to get away with it 90% of the time. The 10% of the time results in excessively desperate attempts to save face. Her smug unwillingness to admit defeat looks ridiculous on the outside, but she doesn't have a lot of support and she really doesn't have the best grip on reality. She's trying so hard to convince herself she has it all together that she doesn't realize she's trying at all.