Overview
It's easy to dismiss Josuke as just another hoodlum -- the pompadour ("regent", in Japan) evokes the image of a 1980s delinquent. But there's more to Josuke than an impeccable coif, even if he will deal vicious beatings for insults to it. Josuke has a "Stand", basically a psychokinetic poltergeist under his control. The pink-and-blue armored "Crazy Diamond" both delivers brutal beatdowns, AND heals/fixes injured/broken, reflecting Josuke's dual natured personality of kindness edged with the infamous Joestar temper. However, reflecting his selflessness, he's unable to use this ability on himself or anything on his person. Despite this ability perhaps being "the kindest of all", as his much older nephew Jotaro called it (the family dynamic is... complicated), Josuke IS a delinquent. He tends to do what he feels is right, whether it's the thing that's "proper" or LEGAL. And generally gets himself in trouble in the process. But he's inherited the Joestar wit, and his quick thinking tends to get him out of what his heart gets him into.
Perks
Stand: Crazy Diamond: A poltergeist; tough, strong fighter, limited ranged attack capabilities
Crazy Diamond is Josuke's Stand, a manifestation of his lifeforce and/or fighting spirit, whose abilities stem from his personality. It is classified as a short-range power-type Stand, and thus possesses incredible physical attributes, with the caveat that it cannot manifest more than six and a half feet (two meters) from him. It is strong enough to bend steel with little effort, fast enough to catch bullets fired in close proximity to Josuke and to throw flurries of punches at approximately 190 mph. It can also strike the firing pin of a bullet and fire it off as if from a normal gun; when using rifle bullets for this, it can accurately hit targets up to 164-229 feet (50-70 meters) away.
Stand Restoration: His Stand can heal people/repair items
Crazy Diamond has the ability to fix items or heal people. This is less about knowing the item's or person's makeup and more about reverting them back to an earlier state in their history -- sort of "rewinding time" for the person or object. There are limits to this ability however. Firstly, Crazy Diamond can't repair anything on Josuke's person, or heal his own injuries. Secondly, he can't cure diseases or slow/stop the progression of natural aging. Third, he can't bring the dead back to life. There is also sometimes a cutoff for how long ago damage or injuries can have been inflicted, after which point Josuke can no longer repair them. However, this tends to be an arbitrary measure that may or may not have any correlation with the object's age. And if he gets distracted or cannot concentrate, he cannot use this ability; if he does, he's liable to warp the job, thus ruining the object -- or the PERSON -- yet further!
Stand Invisibility: Some people can't perceive Stands
Those without Tier ratings generally cannot perceive Crazy Diamond, but the phenomena caused by Stands can be seen by anyone -- non-Tiers can see when Crazy Diamond punches holes through things (or people), picks things up, repairs things, etc. Generally psychics, people with mystical senses/abilities, or ability to see spirits can most easily see Crazy Diamond as it appears. Tiered individuals, even without mystical senses, tend to see Crazy Diamond as a misty pink-and-blue outline. There are other ways to detect the presence of Josuke's Stand without seeing it -- it sets off EMP and motion sensors, it smells of ozone, and it disturbs air currents in an area when it moves. Additionally, even non-Tiered people, if perceptive, may pick up on the "watched" feeling, or the feeling of "the creeps".
Stand Resilience: Stands are more durable than their users
As Stands are reflections of their user's mental or emotional strength, they tend to possess greater physical attributes than their users. Short-range Power-type Stands like Crazy Diamond tend to be tougher than long-range Stands. Crazy Diamond can be flung into a piece of heavy machinery hard enough to destroy said machinery and Josuke is capable of withstanding it.
Joestar Wit: Can quickly analyze situations/actions and pick up on hints
The Joestars in general are usually some degree of insanely clever. Josuke in particular has inherited a great deal of his father Joseph's non-linear thinking, and it gives him a number of abilities. Firstly it can give him insight into how an enemy might be able to attack, thus giving him a clear method of defending himself, and possibly into outsmarting an enemy. Secondly, it lets him draw clues from the environment that, combined with any prior knowledge he might have, can allow him to use things around him to prepare himself for a particular kind of fight and/or to attack from angles and with methods an enemy might not expect. Thirdly, it lets him read a person's facial expressions or tone of voice, or to "read between the lines", so to speak, to draw information from HOW something is said, or what is NOT said.
Hamon/Ripple (Offense): Channel anti-undead energy through self or organic objects
Josuke can produce and control an energy that is similar to pure sunlight and is powerful against creatures that use/run off negative energy, darkness, or life draining. This energy can boost his physical abilities, allowing him to briefly gain enough power to destroy stone or other hard substances. It conducts through his body or can be stored in organic bits like pellets of wood, and also conducts through metal and water like electricity. Josuke can also charge his Stand with this energy so long as Crazy Diamond is in contact with him. He must maintain strict breathing and blood flow to use it however, and disrupting either disrupts his charge/use of this energy.
Hamon/Ripple (Healing): Use Hamon/Ripple energy to heal himself or others
The positive nature of the Ripple energy can also heal both injury and disease. This supplements Crazy Diamond's ability. Via Hamon and meditation, Josuke is able to heal his own injuries. He requires quiet and downtime for this to be a complete healing; however he can make quick "patch jobs" in battle to stop serious bleeding or force out toxins artificially placed into his bloodstream.
NPCs
Roberta< Named E-Tier >: Small flying robot with sensors and medical knowledge for attack and healing
Roberta is a Nurse-Type Bright Feather Shinki, distributed by the Multi Moveable Systems company and manufactured by the FLESH&STEEL company. The Bright Feather model is a combat medic, with the ability to use her medical tools and knowledge for healing or combat. She is lightly armored and not designed for heavy or sustained combat. Her sensors are designed to diagnose injuries, but these can be used to find an enemy's weak points as well. For armaments, she possesses a large syringe-shaped gun that can fire chemical darts of various types, a pair of curved scalpel-like swords, and an electric defibrillator. She also possesses an extensive database of medical knowledge, as well as a large store of chemical knowledge. This allows her to create chemicals to deal with mundane medical issues as well as to speed the natural healing of someone who is injured or sick... or create chemicals to make a variety of negative effects in an opponent (sleep, mild nausea). Roberta can fly when her armor is fully equipped, she is light and maneuverable, and her small size lets her get into places that someone larger wouldn't be able to. Additionally she may store her armaments in a pocket dimension called Slipway until needed; this pocket dimension can't be used for anything but this purpose however.
Complications
We Both Go Down Together: Anything done to Crazy Diamond happens to Josuke
A Stand is a psychic manifestation of the user's life force, shaped by his/her personality. As such, damage caused to Crazy Diamond will transfer to Josuke, at the level it was inflicted on the Stand. This also goes for other sensations -- being shaken, turned around, shoved over, etc. However, this does not work in reverse; Crazy Diamond is not damaged by injuries inflicted on Josuke, nor is his Stand affected if he is picked up and thrown, shaken, pushed over, etc.
Distractions: Repairing requires concentration
Josuke has to be able to concentrate to affect a proper repair of an object or a person. If his concentration is broken, or he is in some mood that would steal his focus -- deeply afraid, nervous, angry, or upset -- he stands a good chance of warping the object, or PERSON!, beyond repair.
I Am Not My Hair: Insults to his hair set him off
It's true, Josuke is incredibly touchy about his preferred hairstyle. But there's a reason. When he was four years old, he developed a dangerously high fever and while his mother was trying to get him to the hospital her car got stuck in a large snowdrift. She might have never gotten out -- and Josuke might have died -- but a mysterious injured high school student, hair in a pompadour, helped his mother get her car out of the snow so she could get him to the hospital. After he recovered, Josuke began styling his hair to match the teen's. Thus he takes insults to his hair as insults to the mysterious injured teen who saved him. With predictable results.
Rebel, Rebel: Josuke's not one to consider the law when acting
As kind and concerned as Josuke is, the one thing he isn't much concerned with are rules of propriety. Or the law. When he decides that a course of action is the right one, he's going to take it regardless of who or what says he shouldn't. He might interfere with a hostage situation to save the hostage HIS way, steal a motorcycle to pursue a fleeing perpetrator, break into a hospital to get information from an injured perpetrator, or any number of other such clearly illegal methods of getting the job done. But he WILL get it done. This is the most likely thing that will get him in trouble, since he seems to prefer asking forgiveness afterwards to asking permission beforehand.
Heal the World: Wants to help everyone, even enemies
Josuke might be a delinquent, but he's aware that other people generally have families and people who care about them. As such, he tries really hard not to kill anybody -- or let anybody die --when he gets into trouble. So complete is his awareness that he will even attempt to heal opponents and people who try to stop him. Though if he's particularly mad at them they may still end up with their noses all over their faces as he purposely warps the repair job...
Money (That's What I Want): Josuke is a little greedy where money is concerned
Josuke doesn't think anything of playing tricks on even close friends and family to part them with a little of their money. Mind, it's not because he's a spendthrift; most of his cash gets squirreled away in a savings account for emergencies. But overall he tends to lean towards moral ambiguity where the acquisition of money is concerned.
No Reptiles: Mild fear of reptiles, major fear of turtles
For whatever reason, Josuke is creeped out by reptiles. He tends to avoid lizards and snakes, and steers clear of turtles in a wide berth. He can focus through this fear if it's really necessary, but it's always going to make him hesitate in a situation. Not to mention that, amongst the Branches and Blossoms of the world tree, giant reptile people isn't completely impossible. And coming face to face with a human-sized reptile is guaranteed to scare the hell out of him.