Another option is a young apprentice of Orochimaru. Orochimaru was always into strange and unorthodox experiments. So, his apprentice could have been exposed to some chemicals during their time with him and developed a chemical release ability. This character would be conflicted, having learned from a villain but now trying to use their power for good in the Naruto world.
Well, it could also be an older character who had been in the background all this time. For example, an old scientist - type character in the Hidden Leaf Village who has been secretly working on a chemical release jutsu for years. Now, due to some new threat in the Naruto world, they come forward with their invention to help save the day. Their knowledge of chemicals and ninja techniques combined would make for an interesting main character.
It could be a new, self - made ninja. Maybe someone who wasn't born into a powerful clan but through hard work and experimentation developed a chemical release ability. This character would have to struggle against the prejudice of those who think traditional ninja abilities are superior.
It could be a long - lost relative of the Third Tsuchikage. This character might have inherited the Dust Release ability and is now on a quest to understand its true potential and use it to protect their village.
Sasuke could be a great main character. His natural talent and his search for power could lead him to discover Laser Release. He might use it to further his own goals and in the process, face new challenges and enemies.
Maybe an older, forgotten character from the Naruto series who resurfaces with the ability to use Black Lightning Release. They could have a hidden past related to the technique and now they're back to make a difference. This character could be someone who was once on the sidelines but now takes center stage.
It can be used as a plot device for a mystery. For example, a series of strange events occur in the village and it's discovered that a rogue ninja with a 'chemical release' is causing them. The main characters then have to find and stop this ninja.
In Naruto fanfiction, a 'chemical release' could be something like a new type of jutsu where ninjas manipulate chemicals. For example, they might create poisonous gases that can be used in combat or to disable opponents. It could also be related to alchemical substances that enhance a ninja's abilities, like a potion that temporarily boosts chakra control.
Maybe a young girl who is the sole survivor of a clan that was wiped out because of their Clay Release abilities. She has to keep her power a secret at first but then decides to use it to avenge her clan. As she grows in power, she becomes an important ally to Naruto and his friends.
It could be an ordinary person who stumbles upon a chemical lab by accident and accidentally causes a mishap. This person then has to deal with the consequences, like facing angry scientists or trying to clean up the mess they've made. Their lack of knowledge about chemicals would add to the drama and humor of the story.
It could be an original character. A young ninja from a small, unremarkable clan who discovers they have the Steel Release ability. This character would then have to navigate the complex world of the Naruto universe, facing both the admiration and envy of other ninjas.
One idea could be a story where a new character discovers a unique chemical release ability that no one has seen before. They could use it to solve a mystery in the Naruto world, like finding out who is secretly poisoning the water supply in a village. Another plot could involve a villain using a chemical release jutsu to create a dangerous fog that makes everyone hallucinate and fight each other. Then Naruto and his friends have to find a way to counter it.
A young orphan girl named Yuki could be a great original character. She has strong Snow Release powers but doesn't know how to control them properly. She meets Naruto and he helps her learn to control her powers while also teaching her about friendship and loyalty. Yuki could have a tragic backstory that makes her a complex and interesting character.