Mightith I inquire about your One Piece OC? Just any information you are willing to share?
I have a few OCs, all belonging in a Marine!Luffy AU I dreamed up a while ago and have yet to write much of at all. I'm not sure which one in particular you're asking about, so I'll give a little bit of an overview on all of them! If there's any more detail you're interested in for any of them, ask away - I'm still developing them so questions are useful :D
Barring Sala (who I've listed last), they're all pirates in the same pirate crew, which is basically the AU verse's replacement for the Strawhats. Some of the canon Strawhats are in the crew (Usopp is the Captain, while Sanji, Chopper and Brook still all end up in the crew, alongside Hachi), but I needed a few more characters to give Usopp a fully-functioning crew! It's not the powerhouse sort of crew the Strawhats are, though...
(All names are given in the Japanese way with family name, where present, listed first)
Howa Akati
Aged 22 years old, Akati is the first mate and the first person to join Usopp at Syrup Island. For the most part, he likes to enjoy life and can usually be seen grinning, but he's also the crew's maturity core and keeps them on-track when they get a little immature. While he's not one for open leadership, he's certainly the type to have ideas and influence on actual leaders.
In combat, he specialises in long-range sniping, much like Usopp, although his preferred weapon is the more traditional rifle. He does also have some pistols for use in closer combat if necessary. While he's not consciously aware of it to begin with, he also has latent observation haki, which was forced out of necessity after he lost the use of his left eye and therefore most of his depth perception and peripheral vision.
Yamishima
At 4'11", Yamishima is the shortest human member of the crew, and is destined to stay that way because he's 19 and fully grown (he has a tendency to pull an Ed from FMA and wear platformed heels to appear slightly taller than he is). He's not a fan of being short, and definitely not a fan of being picked up and carried around for fun by his crewmates (if Akati picks him up one more time...)
Originally a street urchin the crew picked up off the streets in an East Blue island, he primarily focuses on infiltration and thievery. His devil fruit helps with this - the only devil fruit user amongst my OCs, he has the Nagi Nagi no Mi, which is going to give Law all sorts of Feelings when the two of them meet. His primary weapons are knives, which he dual-wields.
(Honestly I just saw the abilities of that fruit and figured there were probably other ways to use it and wanted to play around with that, but I'm also always here for anything that gives Law angsty times)
Pansio Rae
The shipwright of the crew, Rae is also the oldest not-dead member at 25. The crew pick him up at Loguetown, where he barters passage by promising to keep the Going Merry seaworthy until they reach Water 7, which he has an Eternal Pose for. He actually traded away everything he owned except for the clothes on his back and his basic tools for said Eternal Pose, which might not have been the smartest trade in the world, but Rae made it anyway. No-one said Rae necessarily makes rational decisions.
The scar on his left cheek is an example of this - he once antagonised a pirate crew in a pub, and came away with a very raw face courtesy of aggressively rough floorboards. If his twin hadn't saved him, that scar could well have been the least of his worries. That being said, his twin is also a Marine, so after Rae joins a pirate ship family reunions become rather more... interesting. His weapon of choice is a hammer (unlike Sanji, he has no moral hangups about using the tools of his trade as a weapon).
Maikes
Joining the crew in Paradise, shortly after Reverse Mountain, is 22 year old fishman, Maikes. Based on a steelhead salmon, Maikes becomes the crew's much-needed navigator. He idolises Fisher Tiger and the Sun Pirates, but was too young to join them and ended up striking out on his own several years later.
Maikes is also physically disabled; his right arm is mostly paralysed after an accident in his youth and is only capable of the simplest of motions, so while he's still at least as strong a swimmer as the strongest human, he's unable to keep up with his fishmen brethren in the water. Despite, or perhaps because of this, he's a very proud individual and doesn't always think before he speaks, which can result in some needlessly antagonised situations. Fishman karate is also still his combat method of choice, despite being down one arm.
Tourmaline Fleury
The final OC addition to the crew, Fleury is the joint-youngest at 15 years old (although he's still taller than Yamishima!). Mostly quietly-spoken, he has an appreciation for living things that most people his age simply don't have - unfortunately, this is because he's terminally ill and knows he only has a few years left, at most. His family were very reluctant to let him leave home and go exploring, but in the end they were persuaded to let him go. Chopper has made finding a cure for his condition one of his top priorities.
His role on the ship is the helmsman; physical activity can drain him, especially on bad days, and it's not unusual for him to have dizzy spells, but he loves being at the helm of the ship, and it's not usually a taxing responsibility. In terms of combat, Fleury mostly tries to hide and avoid it, but he is a practioneer of kyudo (archery) so as long as he's not too weak to draw his bow he helps with ranged support.
Pansio Sala
The sole non-pirate OC, Sala is Rae's (younger) twin and is currently a Captain in the Marines. Once upon a time he and Rae were close, but after Rae went and joined a pirate crew, their relationship has become very strained on Sala's side of things - he views Rae's current allegiance as a personal betrayal, and can't understand why he did it.
As a Captain, Sala is straight-laced and sticks to the rules as much as possible, although he does care for those under his command and does his best to look after them within the constrains of said rules. Maybe once he would have been willing to stick his neck out a little further, but with his twin now being a known pirate, he's well aware that certain officers higher-up are watching him like a hawk, and he's smart enough to not want to get on Akainu's bad side. His weapon of choice is a hand-and-a-half Carolingian sword, although he isn't a terrible shot with a gun if he has to fight at range.