Talk:How to Play/@comment-36.72.158.62-20150325110450/@comment-26093926-20150325141710

You can use a spare sword. Or take off their troops and carefully drop them to Moderately damaged. Re-equip their troops and they'll reach Shinken Hissatsu eventually as you grind. I also managed to unlock a lot of my Shinken Hissatsu because of Kebiishi spears piercing through troops to drop them low enough. I might be wrong but getting hit might increase chances of activating Shinken Hissatsu.