Well, it depends on the specific fanfic. But usually, there would be a character who has the crystal bloodline as one of the main characters. This character could be an original creation for the fanfic or a reimagined version of an existing Naruto character with the added crystal bloodline ability.
One interesting concept could be the unique abilities that come with the crystal bloodline. For example, the ability to create crystal structures for defense or attack. Maybe the characters with this bloodline can crystallize parts of their body for added protection in battle.
One of the common themes is the search for identity. Since the crystal bloodline is something unique, the characters in these fanfictions often question who they are in relation to their newfound abilities. They might struggle with whether they are still part of the normal ninja community or if they are something entirely different. Also, there is often a theme of secrecy. Because the crystal bloodline can be so powerful and different, the characters may need to keep it a secret at first to avoid being targeted by enemies or even by those within their own village who might be jealous or afraid of their power.
Well, in Naruto fanfic, it's quite common for writers to come up with new types of chakra - based abilities. 'Crystal release' could be one of those. It might be used by original characters created in the fanfic or even given to existing characters in new and interesting ways. For example, a character could use 'crystal release' to form defensive barriers or offensive weapons made of crystal, which can make the battles in the fanfic more exciting and different from what we see in the original Naruto series.
It could be an old hermit who has been living in seclusion. This hermit has mastered crystal release and sees potential in Naruto. He decides to pass on his knowledge to Naruto, seeing him as a key to bringing peace to the ninja world.
Well, there's a fanfiction called 'Crystal Bloodline: A New Power in Konoha'. In this story, the character with the crystal bloodline faces many challenges in the village. They have to deal with both acceptance from some and suspicion from others. The story also shows how they train to master their special abilities, which are really cool and different from the regular ninja techniques in Naruto.
One characteristic is the unique power source. Crystal powers are often introduced, which are different from the typical chakra-based powers in Naruto. For example, they might have special abilities like crystal manipulation for defense or attack.
There might be a mentor figure, an older ninja who has some knowledge about the crystal release bloodline, even if they don't possess it themselves. They guide the young character in understanding and using their powers. For example, they might teach the protagonist how to shape the crystals into different forms like weapons or shields. Another common character could be an antagonist who covets the power of the crystal release bloodline and tries to either steal it from the protagonist or prevent them from fully realizing its potential.
In the fanfiction, the crystal release bloodline could be linked to a hidden realm made entirely of crystals. The main character, who has this bloodline, discovers a way to enter this realm and finds out that there are powerful crystal beasts there. They have to form an alliance with some of these beasts to gain enough power to defeat an evil force that is threatening the ninja world.
Well, in the fanfic, Naruto using crystal release could be part of a mission. Maybe he's in a land where crystal release is common among the enemies. He starts to study their techniques and somehow manages to adapt it to his own style. He could then use it to save his friends during a really tough fight. Like, he creates a huge crystal shield to protect everyone from a massive attack and then turns the shield into sharp projectiles to counter - attack.