Utsuro Clan

The Utsuro Clan (ウツロ一族, Utsuro Ichizoku) was one of Iwagakure's well respected founder clans before it was practically wiped out during the Third Shinobi World War.

Founding
Not much is known about the Utsuro Clan's Founding but it was one of the strongest and most feared clans in the Land of Earth during the clan wars. Though not as feared as the Senju or Uchiha, the clan was a formidable opponent.

Eventually, the Utsuro and a few other clans came together to form Iwagakure.

Third Shinobi World War
During the Third Shinobi World War, many of the Utsuro Clan were deployed into Iwa's Second Battalion – the one which the wiped out by Minato Namikaze. A lot of the others were wiped out in the other battles of war.

Atom Release
The Utsuro Clan Were most feared for their Bloodline Limit; Atom Release. This gives them the ability to condense atoms into sharp, hard scales. The Utsuro used these scales to attack opponents, make armor and weapons and to form barriers and walls to block chakra attacks and physical shrapnel etc. Unlike Gaara's sand, the Utsuro can't lift people or use the scales as transport. There are two downfalls to this bloodline. One: It's rather draining on chakra and hard to control, two: Atom Release is naturally weaker against Earth Release. While it's not completely useless against it, it is still weaker, which is ironic because the Utsuro Clan resided in the Land of Earth.

Trivia

 * The word 'utsuro' (虚ろ) means ' empty ' or 'hollow ' which refers to the technique: Atom Release: Vanishing Tomb where the user encases themselves in a barrier is teleported a short distance away. A bit like the Body Flicker Technique.
 * It is known that the Third Raikage wanted this bloodline for himself.