John Stewart

John Stewart is a member of the Green Lantern Corps, an intergalactic peacekeeping brigade empowered by Oa's light. With his Power Ring, John can manipulate light into solid constructs, making him one of the Justice League's most versatile members. As a former marine, John has a strict sense of of professionalism and duty, placing his obligations to his job above his own desires. Due to John only recently returning to Earth after spending ten years as a Green Lantern, he has struggled to reintegrate himself into a world that is now nearly alien to him. Although known for his strict, no nonsense attitude, John has a soft spot for his favorite movie, Old Yeller. 
=History=
See Here
=Personality=
John is a very disciplined man, owing to his training as both a Marine and later as a Green Lantern. His military service has had a profound effect on his life, to the extent that it carries over into his own personal life. He upholds a strict sense of professionalism, to the point of refusing to initially even engage in romantic encounters while on the League Watchtower whenever he was 'on duty'. Likewise, at home, John kept his home in order, to the extent that his girlfriends had commented on the fact he even folds his socks. Combined with his sense of duty is a strong loyalty to not only the Green Lantern Corp, but also the Justice League and the country of his origin, the United States. When it comes to fellow members of the League (or the Lantern Corp), John expects the same level of professionalism of his comrades. He has often berated the rookies or more freespirited members of the League, such as Flash and Supergirl, for their reckless antics. 
John has certainly lightened up due to his time with the League. He has fallen in love with Shayera (and been betrayed), became unlikely friends with the irresponsible Flash, and learned to trust the judgment of his comrades, even when faced with his own doubts. Consequently he's been known to crack a joke a few times, socialize with his fellow league members, and use his Power Ring in more frivolous ways than he had in the past. While it's certainly true that John has learned to relax and unwind more, he can still be a hardnosed discipliner and is typically the one to take the lead when it comes to training new recruits or practicing drills for team building purposes. But in spite of his tough exterior, John still has a softer side that belies his very military attitude. When he believed himself to be responsible for the destruction of a planet, even on accident, he was willing to accept the charges against him. There's a part of him that still idolizes the heroes of the Justice Guild comics and causes him to still get choked up when watching Old Yeller again. There is also a part of him, evidenced in his own nightmares, that fears he is not the master of his Power Ring or of his own destiny and that he is just an extension of the will of other forces. Although he has confronted these fears before, they remain a part of him and he has often wondered what his life would have been like had he never became a Lantern.
==Strengths==
The Ring: The Power Ring works as an extension of John's will, giving form to whatever he can imagine. Primarily it can be used to create solid light objects, which can be used both defensively (such as creating shields) or offensively. It also has many functions, such a personal forcefield (which he keeps active during battles), the ability to travel in space or water without he need for air (which is seemingly generated by the ring itself), or for carrying and towing groups of people or large objects. Additionally John has used it for illumination in normal light, or other types of light such as thermal or x-ray in order to detect heat signatures or see through objects. Additionally, it can be used to generate clothes of the user's own choosing to go on top of whatever John is already wearing. In spite of all this, the Ring requires recharging at least once a day (though it's possible to go without for longer than a day, John risks it running out on him at any time). In order to recharge, the ring has to take power from a Power Battery, which is usually hidden in a Pocket Dimension to prevent it from being stolen.
Physical: Being a former Marine, John has had plenty of combat training and even without the ring, has demonstrated himself to be a capable fighter both with his fists and with a gun. In spite of the fact his Ring gives him great powers, he keeps himself physically fit and would be considered to be in peak physical form. 
Mental: John is very much a soldier and applies discipline into all aspects of his life. Although being a Green Lantern does require a certain code of conduct, he applied this same restraint to his duties with the Justice League despite being a relatively informal organization. As a result, John is a very focused individual and works effectively in a team as either a leader or as merely a player, easily giving orders and taking orders. 
==Weaknesses==
Strength: Using the ring requires constant concentration on the part of John Stewart and as a result, any more complicated constructs than simple shields can be disrupted with a powerful enough blow. Because these constructs are light turned solid, they can be broken by enough of a powerful force, which has been demonstrated to cause the Green Lantern backlash of disrupting his concentration. Because the ring requires constant concentration, being knocked out will cause all constructs (including personal forcefield) to be disabled, leaving John otherwise unprotected. The ring itself can only hold a charge for a little over a day, so failing to recharge it can be disastrous. 
Mental: As a result of his military attitude, John often finds himself at odds with dealing with more carefree members of the League (or the Lantern Corp). Although his association with them has eased up some of his attitude, he still has difficulty in expressing emotion without fear of appearing unprofessional. As mentioned before, John retains some regrets on becoming a Lantern, often questioning whether he is in control of his own fate and about the other life he could have had.