X-Blades

When you reach the level “Underground Hall” (which is the second last stage) proceed down the hallway until you reach the door to the main arena. Do not enter the arena, but stay against the wall where you can still see the monster run back and forth past the door. The game teaches you to use the combo , , which you'll need to use to defeat this boss. You can use this combo over and over again until the boss dies without ever entering the room. Making a manual save before attempting this can be beneficial in case you walk into the room by accident.

Manually Save to be safe before this achievement. After the Hall of Columns level, you'll be in the Underground Hall where it displays the only way to defeat the boss. DO NOT enter the arena, the Boss will keep running against the door so it cant reach you. Stay all the way back and keep hitting the actions displayed which are (,,) and you should get your Flawless victory.