Iron Skin

 is the shinobi's adaptation for the physical conditioning technique utilized by Samurai. The user utilizing his chakra would wrap his entire body into an invisible shroud of chakra that is only visible to the three known dōjutsu to man. This is a virtue of natural taijutsu skills (physical condition) and further augmentation by iron-like skin. However, instead of just creating an invisible force-field of chakra, the technique also augments the user's tissues by reinforcing them with chakra particles. User's skin becomes as hard as titanium steel and their muscle and bone tissues become considerably denser than the tissues of an ordinary human, granting them much greater resistance to physical injury than an ordinary human. When his bio-electric aura interacts with this force-field it forms, the ultimate shield. They can willfully utilize their "aura/force-field" strengthening it's power to a greater degree to provide an additional defense against certain levels of physical and energy attacks for a considerably short period of time, but doing so can endanger them should the attempted feat prove inefficient for any reason. They can utilize their aura by expanding it around a person(s) or object(s) to enable their structural stability when lifting or traveling with them.