Background of the Black Dragon
Clan:

The Black Dragon Clan, an elite group of Shinobi born with a unique bloodline, the "Shuyurogen" a trait making the users eyes black with one of many different colors in the center, the center sunbursts into the black.

Depending on that users abilities and strengths the color
was different :

Green the user of the Earth Element.
Red the user of the Fire Element.
Purple the user of the Wind Element.
White the user of Lightning Element.
Pink the user of the Poison Element.
Blue the user of the Water Element.
Grey the user of the Shadow Element.
Yellow the user of the Light Element.

There are also some with rare eyes:

Gold the user of the Light and Wind Elements.
Ember the user of the Earth and Water Elements.
And Silver the user of Shadow and Lightning.
But a few in the clan history had been born with the Ice Blue Eyes, giving them the ability to Harness Ice, Wind, and Shadow. Each user though different all has the ability to anticipate an opponents movements easier and to see an opponents chakra flow. The Black Dragon Clan was mainly used for assassinations and S-ranked missions because of these abilities. The Black Dragon Clan was also well known for their special Taijutsu and Ninjutsu Techniques because of their bloodline. They were also masters of forging weapons of high quality and infusing
them with chakra. 4 of the Legendary Blades are examples of their forging abilities, these blades were wielded by the leaders of the clan, each leader
was given a blade and had to forge it to fit his/her specific style of fighting. There were 3 leaders of the Clan originally and they each forged a blade creating the 3 Dragon Blades, Later on a 4th blade was created by Turin "Shyugen" the Black Dragon Blade, a blade of power and pure devastation if wielded by a member of the Black Dragon lineage. Each member of the clan went through rigorous training in each form of fighting, making some of the most rounded off, dominant and well developed ninja on the entire continent if not the world. The village is rather small but each member is a trained assassin by the age of 16, as they are trained rigorously starting at the age of 6, even as small children their joints were dislocated as to help them with escaping, flexability and dealing with excrustiating pain.


There are several advancements in the
bloodline itself that are very hard to obtain, these bloodline advancements are achieved by the most dangerous, ferocious, and ingenious ninja in the clan:


"Khuyurogen"

Being Crimson red colored eyes with a black sunburst center, these eyes are prefered more among the dark users of the clan, the user still has the same abilities of their Shuyurogen but they are more keen and easier to use, another ability that is introduced is the users ability to go into a rage that increases their over all strength by almost double and they can also take an unbelieveable amount of pain, even to the point where the user could die but they will keep fighting with the same ferocity. This advancement in the bloodline is called the Khuyurogen.


"Bhuyurogen"

This advancement in the bloodline gives the user Sapphire blue eyes with a black sunburst center. This is part of the bloodline more favored by those of the light side users in the clan, the user still can use there abilities from the Shuyurogen, but another ability added is the user is the ability to Use their chakra to heal wounds easily and without using up as much chakra, this user is able to control their chakra almost perfectly and can increase their over all strength and speed. This advancement is called the Bhuyurogen.


"Ghuyurogen"

One of the harder advancements in the bloodline looks like emerald green colored eyes with a black sunburst center. This user can use their abilities at a higher level and almost perfectly, but the other ability added is the ability to perform genjutsu techniques of the clan, these techniques are the hardest to learn as they are very strenuous on the user, but the user is able to after time use the genjutsu techniques more easily and without much loss of chakra. This advancement is called the Ghuyurogen.


"Dhuyurogen"

The Bloodline can be advanced to an even higher level through unknown methods. The Users Eyes Become Pure White with a Black Sunburst Center, the advanced bloodline is called the Dhuyurogen. This gives the user the ability to use there original elements but at a higher level, it also increases there chakra flow immensily. They can still see a person's chakra flow, and the user can predict a persons movements and actions a lot faster, but the new ability also gives the user the ability to manipulate there chakra on a completely new level, increasing there overall abilitys far greater then before. The Ultimate Bloodline of the Black Dragon clan, but only a few have ever attained this, those being the 2nd head of the clan, and the current head of the clan.