In some 'naruto bloodlines experiment fanfiction', there could be the concept of a failed bloodline experiment that leads to a character having unpredictable powers. This can add a lot of drama and mystery to the story as the character tries to control or understand these new abilities. Also, the fanfic might explore how different characters react to this new and potentially dangerous situation.
Often, Naruto himself is involved. Since he is the main character of the original series, many fanfictions like to put him in the center of bloodline experiment stories. He might be the subject of an experiment or be the one trying to stop a dangerous bloodline experiment.
In some fanfictions, one could be the Sharingan, which gives abilities like seeing chakra and predicting moves. Another might be the Byakugan, with its great vision powers. And the third could be something unique like the Ketsuryugan, which could have powers related to blood manipulation.
Maybe he uses some kind of special jutsu. It could be a new form of his shadow clone jutsu where the clones are able to analyze and then copy the bloodline traits of the opponents they encounter.
In the 'naruto has 3 bloodlines' fanfiction, these bloodlines can have a profound impact on the story. For instance, if one of the bloodlines allows Naruto to communicate with animals in a special way, it could lead to new alliances and ways of gathering information. A bloodline that enhances his ninjutsu in a unique way might make him the target of other villages or rogue ninjas who want to steal his power. And a bloodline that gives him the ability to heal others more effectively could change his role within the village from just a fighter to also a healer, which would completely shift the relationships he has with other characters and the overall direction of the story.
Well, in some Naruto fanfictions, a disease could be used to create a really unique plot. For instance, if a disease was created that specifically targeted the Kekkei Genkai holders. It would force the different clans to work together to find a cure. This would be a huge shift from the usual clan rivalries. Maybe the disease was created by a rogue ninja who wanted to wipe out all those with special bloodlines to gain power for himself.
In this fanfiction, the Sharingan from the Uchiha clan is an obvious choice. It has so many abilities like the ability to copy jutsu and predict movements. Naruto could become even more of a prodigy if he absorbs it. Also, the Aburame clan's ability to control bugs could be quite interesting. Naruto could use bugs for reconnaissance or even in combat in ways that are different from his normal fighting style. And the Inuzuka clan's connection with animals, if Naruto could absorb that bloodline, he might be able to form a stronger bond with his summons or other animals in the wild.
The six bloodlines in the 'naruto has 6 bloodlines fanfiction' could be really diverse. It might start with the Senju bloodline which is known for its great chakra reserves and strong life force. Then there could be a bloodline related to some sort of space - time manipulation, like a new version of the Kamui ability. There might also be a bloodline that gives the user the ability to communicate with animals in a more profound way, similar to but different from the Inuzuka clan's bond with dogs. Since it's a fanfiction, the author has a lot of creative freedom to come up with these bloodlines.
The power system in Naruto is one factor. The idea of chakra and how it can be manipulated in various ways is quite experimental. It allows for a wide range of abilities and combat styles. Also, the character arcs often deviate from typical hero - villain dynamics. For example, some characters have complex motives that are not simply good or bad.
In the realm of Naruto all bloodlines fanfiction, there's also the aspect of bloodline combinations. Writers might create a character who has a combination of two or more bloodlines, resulting in completely new and unforeseen powers. This can lead to very creative and unpredictable story arcs.