Blade Steal

Blade Steal  (模倣剣技, lit. Imitation Sword Techniques) is a martial art technique utilized by Ikki Kurogane.

Description
Blade Steal is a technique that Ikki Kurogane had created, which lets him "steal" someone else's swordsmanship due to no one wanting to teach him anything. He is able to use his incredible insight to trace the roots of any style he sees, thus letting him grasp a styles techniques despite not seeing it performed in front of him as shown when he was able to uses Ten'i Muhou through helping Ayase Ayatsuji improve her swordsmanship. Through the use of his Blade Steal, he is able to grasp ones' sword style in a couple of minutes as well as find their flaws, then Ikki is able to perfect them creating a superior version. He is able to steal styles that aren't sword techniques.

Drawbacks
Though Blade Steal is a strong technique, which grants him an advantage in a fight, it can take a while for him to do so based on how much one has trained and honed them as shown when he stole the Imperial Sword Style of Stella. This is further stated as he stole Edelweiss' swordsmanship as he was incapable of utilizing it to the fullest since it still produces too much noise among other major differences from the two styles.

Copied Styles and Techniques

 * Ouma Kurogane: Kyokujitsu Isshin-ryuu
 * Stella Vermillion: Imperial Sword Style
 * Kaito Ayatsuji and Ayase Ayatsuji: Ayatsuji Itto-ryu
 * Edelweiss: Edelweiss's Swordplay
 * Yagyuu Shinkage-ryuu
 * Yuuri Oreki: Yuuri's Swordsmanship

Trivia

 * Ikki is mentioned having learned 126 sword styles in total as of between Vol 1 and 2.