Perfect Vision

Perfect Vision is the original technique of Ikki Kurogane and what his Blade Steal was derived from.

Description
"The principle he spoke of wasn't a notion limited to the here and now. That predictability of human thought was a firmly-rooted identity, not something that could be changed in an instant. However much the person himself wants to outsmart that identity, even the thought of outsmarting it arises from the identity itself, and therefore couldn't escape Ikki's perception. By stealing the opponent's identity, Ikki seized all those thoughts and feelings."

- The description of Perfect Vision

His Perfect Vision is a technique that Ikki created, which is the end result of him training his insight over the years due to no one wanting to teach him anything he instead decided to learn from others through observation. Unlike Blade Steal where he "steals" another person's swordsmanship or technique, Perfect Vision is a technique, which lets him see through his opponent through tracing their small tendencies and personalities in a battle to where he is able to predict and react their next moves.

This is first shown in his fight against Shizuya Kirihara during the Selection Battle Arc, where Ikki traced all of the damage that he took from his arrows, letting him predict all his moves despite being cloaked and avoided Million Rain. As a testament to the usefulness of Perfect Vision was shown in his fight against Edelweiss, where he was able to predict at least three of her moves beforehand despite not being able to see her slashes although Ikki still needed Ittou Shura to keep up.

Trivia

 * Perfect Vision is said to approach the mystical mind's eye.
 * The actual translation for Perfect Vision is "Complete Control", but it was instead known as "Perfect Grasp" in the actual light novel series.