His powers would likely incorporate more water - based elements. He might be able to control mist in ways that are more powerful and sinister than normal. For example, he could create mist that not only obscures vision but also drains the chakra of those who are trapped in it. His physical abilities could also be enhanced in a way that is more in tune with the Mist's fighting style, like being more stealthy and unpredictable in combat.
If Naruto becomes the Demon of the Mist, his powers could change significantly. He could gain the ability to transform into a mist - like form, allowing him to pass through solid objects or evade attacks easily. His Rasengan might take on a new form, perhaps with a blue - green hue like the color of deep ocean water, and have added effects like freezing or numbing opponents on contact. He could also develop the power to summon creatures from the mist, such as large, shadowy beasts that can fight on his behalf.
Naruto's powers would be different in several ways. Firstly, his connection to the Nine - Tails might be altered. Instead of the usual fire - based chakra of the Nine - Tails, it could mix with the water - based nature of the Mist, creating a unique and more powerful energy. He might be able to create illusions within the mist, not just simple visual ones but ones that can affect the mind and senses of his opponents. His speed and agility could increase, allowing him to move through the mist like a ghost. His overall power would be more in line with the dark and mysterious nature of the Demon of the Mist, with abilities that are both alluring and terrifying.