He could start by simple things like creating ice cubes at will. Then progress to making small ice sculptures, which could later grow into larger and more complex ones. Eventually, he could learn to create ice storms or even entire ice landscapes.
One interesting Naruto ice powers fanfiction could involve Sasuke somehow obtaining ice powers. Maybe through a forbidden jutsu experiment gone wrong, he now has the ability to create ice sculptures that can also be used as weapons. For example, he could make ice shurikens that are much more powerful than the normal ones and have a freezing effect on the opponent.
Naruto's Rasengan could be encased in Elsa's ice to create a more powerful and destructive attack. The ice would make the Rasengan even more solid and increase its impact.
Another way their powers could combine is in the area of mobility. Spider - Man can move quickly through the city, but Elsa can create ice bridges and paths that can cross large gaps or even over water. So, if they were on a mission together, they could use these combined abilities to get to places faster. For example, if they were chasing a villain who escaped to an island, Elsa could freeze a path across the water and Spider - Man could swing them both along the path at high speed.
A Danny Phantom ice powers fanfiction could explore how his friends react to his new power. Sam and Tucker might be both amazed and a bit worried. They could help Danny test his powers in a safe environment, like an abandoned warehouse. And Danny might use his ice powers to create cool (pun intended) sculptures for fun, but also discovers that the power has a deeper connection to his family's ghostly heritage.
There could be a fanfiction where a character with ice powers is actually an enemy in the Percy Jackson world. They are trying to freeze over all the water sources, which would be a huge threat to the demigods. Percy and his friends have to figure out how to stop this ice - powered foe. They might discover that the only way is to find a way to combine fire and water powers in a unique way, like using the heat from Hephaestus - forged weapons along with Percy's water control to melt the ice and defeat the enemy.
In Miraculous Ladybug fanfiction, ice powers can add a whole new dimension. They might be given to a new character, perhaps a villain. For example, a character with ice powers could freeze Paris, creating a unique and challenging situation for Ladybug and Chat Noir to overcome. It could also be a power that a Miraculous holder temporarily gains, leading to interesting plot twists.
Elsa's ice powers and Spiderman's web - shooting could create some interesting combinations. For example, Spiderman could use his webs to swing around Elsa's ice structures, giving him new vantage points in a fight. Also, Elsa could freeze water in the air and Spiderman could attach his webs to the ice formations for extra mobility.
In the long run, Elsa's powers could inspire new Ninja techniques. Ninja are always looking for ways to improve their abilities, and seeing Elsa's ice powers might give them ideas for new ways to manipulate chakra to create similar effects. This could lead to a whole new branch of Ninja techniques. And as she becomes more involved in the Naruto plot, her powers could be the key to defeating a major villain that the regular Ninja techniques are not enough to handle. For example, if there was a villain who was immune to normal attacks but vulnerable to extreme cold, Elsa's ice powers would be crucial in the final battle.
Hiccup is adventurous and curious. He would be intrigued by Elsa's ice powers and her reserved nature. Elsa, on the other hand, is cautious and has been through a lot with her powers. Hiccup's boldness might initially make her a bit uncomfortable, but his kindness would draw her in.