One jutsu he could invent is the 'Elemental Mimicry Jutsu'. With this, Naruto could temporarily take on the properties of any element he has encountered. For example, he could become as fluid as water to slip through attacks or as solid as earth to withstand powerful blows.
Another interesting jutsu could be the 'Time Warp Clone Jutsu'. Naruto would create clones that exist in a slightly different time frame. These clones could act as scouts, seeing a few seconds into the future or past of a battle situation. They could then relay this information back to Naruto, giving him a strategic advantage.
If Naruto invented the 'Energy Absorption Jutsu', it could change the plot significantly. He could absorb the chakra or energy of his enemies, weakening them while strengthening himself. This would make him an even more formidable opponent and could potentially shorten battles, as he could quickly disable foes.
Maybe he invents a gun that can fire chakra - enhanced bullets. This way, it combines the power of ninjutsu with the concept of a gun.
Sasuke could be one of the people to teach Naruto new jutsus. They have a friendly rivalry and Sasuke has some unique jutsus like his Rinnegan - related abilities. He could teach Naruto some aspects of the Rinnegan's power, or at least how to counter it more effectively which could be considered a new 'jutsu' in a sense.
There's also the 'Inferno Storm Jutsu' in some fanfictions. It creates a large - scale storm made entirely of fire. The fire in this storm has different intensities, with the center being the hottest and most destructive. It can cover a large area, making it a great offensive move against groups of enemies.
One creative use is turning the bubbles into mini - prisons. In some fanfictions, Naruto can trap enemies inside the bubbles, which are then made unbreakable. This is a really cool and unique way to use the jutsu.
There could be a jutsu that allows for instant teleportation across long distances. This jutsu might be a new discovery in the fanfiction world, perhaps created by a character who has been experimenting with space - time ninjutsu. They might use it to quickly get in and out of battles or reach far - off places in a blink.
He could invent a new type of transportation device, like a flying platform that ninjas can use to quickly move around. It would be powered by chakra and could be controlled with simple hand gestures.
One creative interpretation could be a story where Naruto discovers a new form of the healing jutsu that can not only heal physical wounds but also emotional traumas. This could lead to him helping characters like Sasuke heal the deep - seated emotional pain from his past.
One creative interpretation could be a new form of Rasengan. Maybe a Rasengan that can split into multiple smaller ones upon impact, like a cluster bomb. This would be a powerful jutsu as it could cover a wider area and hit multiple targets at once.
In Naruto fanfiction, cheat codes can drastically change the use of jutsu. They might allow a character to instantly master a jutsu that usually takes years of training. For example, a cheat code could give Naruto the ability to use the Rasengan without any training from Jiraiya. It's a fun concept that adds an interesting twist to the Naruto universe.