Since the Akatsuki often deals with sealing techniques, Naruto's skills with the Nine - Tails' seal could be enhanced in a different way. He might learn to better control the Nine - Tails' power without relying on the methods taught in Konoha. Also, his physical abilities could be trained differently. Maybe he'd focus more on speed and stealth, which are qualities often valued by the Akatsuki.
Naruto's powers would develop in a more balanced way. Tsunade is not just about brute force like Naruto sometimes tends to be. She would encourage him to learn other aspects of ninjutsu. So, in addition to his regular attacks, he could develop some defensive jutsus based on Tsunade's teachings. Also, his Sage Mode might be enhanced as Tsunade could provide insights on how to better control and utilize natural energy.
In a fanfiction where Naruto is in the Akatsuki, his character would grow in terms of understanding different perspectives. He'd interact with characters who have very different backgrounds and motives from his friends in Konoha. His sense of loyalty would be tested as he'd be in a group that is generally considered the enemy. This could lead to him becoming more independent in his decision - making, rather than relying on the approval of his village. He might also become more calculating, as the Akatsuki often have to plan their moves carefully to avoid detection and achieve their goals.
His character would likely become more serious. Madara's influence would make Naruto think more about power and strategy. He'd be less impulsive perhaps.
His chakra control might improve in a different way. Sesshomaru's precise and refined combat style could force Naruto to have better control over his chakra. For example, he might learn to use his chakra more sparingly like Sesshomaru uses his demonic energy.
Naruto's powers would likely be a blend. His existing ninja abilities like shadow clones might be adapted to Mandalorian combat scenarios. He could use his clones to create diversions while he attacks with Mandalorian weapons. Also, the Mandalorian training in stealth and marksmanship could make his ranged attacks more effective, adding a new dimension to his power set.
Well, it could be that there's a plot device like an ancient artifact. This artifact might have the power to draw out and combine the Akatsuki powers. The Akatsuki members themselves might be tricked into contributing their powers to this artifact, and then the protagonist or an antagonist gets hold of it and gains all those combined powers. It's a common trope in fanfiction to use such magical or mysterious items to bring about extraordinary power combinations.
His character might be more hardened. Growing up with Yahiko, he'd be exposed to the harsher side of the ninja world earlier. So he'd be less likely to trust blindly.
Naruto would be more disciplined. Gai's strict training regime would make him more focused on his goals.
Naruto's character would likely be more distrustful of traditional ninja institutions. Since he's raised by a rogue, he might see the established ninja villages as corrupt or overly restrictive. He could be more rebellious and less likely to follow orders blindly.
Naruto might become more sensitive and perceptive. Since kunoichi often have a different way of looking at things compared to male ninjas, Naruto could pick up on those traits.