The child might have Sasuke's dark hair, which is a very prominent feature in his family. And perhaps Sakura's green eyes, which would be a beautiful combination. They could also inherit Sasuke's angular facial features along with Sakura's rosy cheeks.
Well, considering Sasuke's Uchiha heritage, the child could have the characteristic Uchiha dark eyes that seem to hold a lot of mystery. But also, from Sakura, they might get her fair complexion. Their hair could be a dark shade like Sasuke's but with a bit of a soft texture like Sakura's. Maybe they would have a small, delicate nose like Sakura's, which would be a contrast to Sasuke's more prominent nose.
Well, since Naruto has such a sunny and energetic look, the child could have that same kind of positive glow about them. Their hair would be a bright blond, like Naruto's, but might be a bit longer or styled differently. In terms of their eyes, they could have Kushina's piercing red eyes, which would give them an intense and determined look. Their build might be more like Naruto's, athletic and well - proportioned, but with Kushina's grace in their movements.
It's possible that the second child's abilities are more latent at first. While the first child might have shown early signs of great power, the second child could seem ordinary in the beginning. However, as the story progresses, they could develop an ability that is even more powerful than the first child's. For example, the second child might discover a new form of chakra control that is unique to them.
The child's character can be developed by giving them unique goals. For example, if they want to become a better ninja than their parents, it would drive their actions and decisions. Also, showing their relationships with other characters, like their grandparents or their parents' friends, can shape their personality. Their reactions to different situations, such as facing a difficult mission or a family argument, are important too.
Sakura would likely develop more patience and strength as she manages a growing family. She's already a strong character, but with a second child, she'll have to learn new ways to handle the chaos. Sasuke, on the other hand, might become more in touch with his emotions as he sees his family expand. He could start to understand the importance of being present more often.
The child could create new shared experiences for them. For example, they would celebrate the child's birthdays together, take family vacations, etc. These shared memories would strengthen their bond. Also, seeing each other in a parental role could make them respect and love each other in new ways. Naruto might see Sakura in a more motherly and tender light, and Sakura might admire Naruto's fatherly instincts even more.
The character could be developed through their relationships. For instance, their relationship with their parents. If Sasuke is still somewhat distant due to his past, the child might strive to get closer to him, which would shape their personality. They could also have a strong bond with Sakura, learning medical ninjutsu from her at an early age.
One possible storyline could be the child's struggle with living up to the legacies of their parents. Sasuke and Sakura are both very powerful ninja, and the child might feel pressured to be just as great. Another could be the child making their own unique mark in the ninja world, perhaps by developing a new jutsu or forging new alliances.
An example of a child's appearance description is as follows: His (her) big bright eyes were clear and bright as if they could see through everything. Her long eyelashes fluttered like two beautiful wings. Her round face was slightly pink and looked very cute. His black hair was soft and delicate, dancing gently with his (her) movements. His slender figure, slender fingers, and healthy and lively appearance all showed his (her) cuteness and liveliness.
In fanfiction, Sasuke is often depicted as a strict yet loving father. He might be distant at times because of his past, but he always has his family's best interests at heart. For example, he could be strict about his child's ninja training to ensure they can protect themselves. Sakura, as the mother, is usually the more affectionate one, always there to comfort the child when they're sad or hurt.
Some writers will describe the child's appearance based on their abilities. Since Naruto has a strong physical build due to his ninja training, the child might have a somewhat athletic build as well. If they inherit Shion's spiritual powers, they could have an otherworldly glow about them. Their hair could be long like Shion's or short like Naruto's, depending on the writer's vision. Maybe the child has a tattoo or marking on their body that is related to Shion's spiritual lineage, but in a more subdued form so it doesn't overpower their overall ninja - like appearance.