For a character like Gaara, his development in a Law and Order fanfiction could be really interesting. Gaara was once feared and alone. If he becomes part of the law - making or law - enforcement in Suna, he could use his own past experiences of being ostracized to ensure that the laws are fair to everyone. He could start to open up more as he works with others in the legal system. His character could evolve from a brooding, isolated figure to a respected leader in the shinobi world's Law and Order structure. He might also develop relationships with other shinobi from different villages as he attends international law - related meetings, which would further expand his character.
Take Sakura for instance. In a Law and Order fanfiction, she could initially be a bit over - confident in her medical ninja skills. But when she gets involved in cases where she has to provide medical evidence in legal matters, she realizes she needs to be more precise and detail - oriented. This forces her to study more and become more professional. As she works with the law enforcers, she also develops her people - skills, learning how to communicate better with patients who are also witnesses or suspects. This multi - faceted development shows how her character can grow within the context of Law and Order.
You can start with a character like Naruto who has always been an outcast in the village at the beginning. As he gets involved in the Law and Order aspect, he could learn about discipline and the importance of following rules for the greater good. His character development could be shown as he goes from being a bit of a rule - breaker to someone who enforces the law fairly. For example, when dealing with a case involving a group of kids stealing food because they are poor, Naruto could use his own past experiences to find a more compassionate solution while still upholding the law.