The sorinnegan(meaning reincarnating sky eye) is a kekkei genkai said to have been made when the white wizards gained the reincarnating ability. Several sight related jutsu can only be used by a sorinnegan user.
The sorinnegan's first, and most well known ability is alowing the user to fly anywhere, even into space, without being damaged by any damage that would normally be caused by the flight, such as the inability to breathe while in space.
It's second, and lesser known ability is known as the multi-summon ability. This ability alows the user to summon just about any kind of material. Noone knows where it comes from, and it could just be generated. They can also control it telepathicly if they can see it. With experiance, it is possible to make a solid thing apear to be liquid by summoning, and dis-summoning parts of it.
It's third ability is to be able to make clones of themselves that don't just vanish when hit. Even though they don't vanish when hit, they are still made of different things, and thus, they can gain special abilities. For example, a clone made from plants might be able to merge with other plants, make fruit, etc. The only way to make one of the clones vanish is to kill the origional, kill them as you would a normal person, disconect them from the origional(possibly by taking their connection part from them), or destroying their conection part. The connection part is the part of them that, as the name says, connects them to the origional, letting them live. It also supplies magical energy to them, alowing them to become full copies, after about a day. They normaly take the place of organs like the heart, stomach, or brain.
It's fourth ability is to be able to generate a sixth kind of chacra.
It's most powerful, and possibly last main ability is to copy any kekkei genkai that it sees, instantly, as if the user had it. It will not, however, be passed down to their children. Nor will any future white wizard be able to use the copied kekkei genkai, until they unlock the sorinnegan. It can even surpass certain blocks that a kekkei genaki may have. This alows them to access all forms of the kekkei genkai without the need to do the same training as the target. The only drawback to this is that they can only get to the level the target was at instantly, the rest can only be activated by the same means as the target.
The sorinnegan has a few secondary abilities that are not only available to it.
Its first secondary ability is the ability to see a person's main chacra field. This lets them see when a person is gathering chacra, when they are in a genjutsu, or, when they are in the dark, see where they are. The only thing it cannot see is where chacra points are, even if a jutsu is being used.
The sorinnegan's second secondary ability is the ability to be able to master all five chacra elements easier.
It's third secondary ability is to be able to create very powerful energy blasts, and control them as the user wishes.
It's fourth secondary ability is the ability to create magical symbols in the air.
It's fifth secondary ability is to alow the user to cast spell links.
The sorinnegan has many side effects, but not all are bad. The main bad side effects include: Possible death when more than one sky clone is made at a time; Blurred vision for a few seconds when activating, or deactivating(when in battle, this could get you injured, or killed); not deactivating when knocked unconscious, and thus using up all of the user's energy; and sometimes making it impossible to stop noticing little things, such as the number of balls in a ball pit, every word on a page, etc.(this would distract the user in a battle, and could also overload the user with information). Some good side effects include: Being able to tell what kekkei genkai a person has; being able to see invisible things, and being able to comprehend whatever the user sees.