Aragami: Shadow Edition

You will need to have at least 4 skill points available to you by collecting enough Scrolls to purchase Shadow Kill alone. You will first need to unlock Shadow Creation (1 point) and Shadow Vanish (2 points) before it becomes available. I believe these values are correct. Let me know if not and I will change them.

Open the skill menu and under Aragami skills, on the right side will be the required skill.

I unlocked this achievement at the start of Chapter 5 with the first patrolling guard. Approach from behind quietly, then press and hold the button to perform the stealth kill which is pretty sweet. Your achievement will unlock.