Before you make your way to the boss area, equip the Shinobi Firecracker tool or one of its upgraded forms, and add both snap seed and fistful of ash to your quick items bar. At the entrance to the boss area, open up your inventory and plop a Gachin's sugar or Gachin's spurt fall. Move toward the back of the area while keeping to the extreme left. The boss will spawn halfway through but should fail to notice you. Note that the monk has her back to you right now, but you won't be able to perform a stealth death blow on her just yet. Move closer to the monk while being careful to stay behind her, then use a snap seed. This will make her a coward and take a step backwards while still remaining oblivious to your presence. You may use up to three snap seeds here, using any more doesn't seem to have an effect. Switch to the fistful of ash or Shinobi Firecracker tool to continue forcing the boss backward. Remember to wait for the monk scouring animation to end between uses. Three snap seeds and a total of five fistful of ash or Shinobi Firecracker tool uses should be enough. Move to the stone column right behind the monk, lock onto the monk, jump backwards into the stone column, then hit jump again to jump off of the column and towards the monk. If you see the red prompt for a stealth death blow, hit the attack button. If not, try redoing the jump to get more height or use fistful of ash or Shinobi Firecracker a few more times to get the boss closer to the column. And that's all there is to it. If this guide helped you, don't forget to leave a like, maybe even subscribe and hit that bell icon to be notified when I upload my next video and I will see you in the next one.