Bloodstained Perception

Bloodstained Perception (勘血塗れ, Kan Chimamire) is a form of sensory sight available through the Kerryūgan.

Overview
Once the user's eyes become crimson through the activation of the Kerryūgan, they become able to see more than the average man. Unlike most dojutsu though, the eyes of blood don't allow the user visualize chakra. Instead, these eyes grant the user the ability to detect and see blood.

This ability is rooted in the fact that the Kerryūgan actually grants the ability to sense iron. Hypothetically a user of this skill can view and sense iron anywhere. Using this on blood is its most effective use however. Being able to detect blood allows the user to sense beings with the liquid even when they aren't visible to their eye. This is very effective for discerning the location of hidden adversaries. As long as there is blood, the user can sense it.

If the user lays an eye on their target, they can view their circulatory systems (or whatever contains their blood). This technique allows for an effective means towards keeping track of an elusive foe. The sensory enabled by this technique allow the user to detect any blood in the user's vicinity, either through sight or basic sensory.