Quote Originally Posted by Forum Explorer View Post
As far as I know the ninjas are otherwise ordinary humans who can use techniques to enhance their abilities. Very few of them are actually stated to be more resiliant to damage then any other human.
And when they get hit by a high-level technique, most ninja die instantly. However, this is very rare with the large variety of feint and defensive techniques they have (clones being the most basic/common), combined with all ninjas having super-agility.