O’Rin of the Water is a mini-boss in Sekiro: Shadows Die Twice, located in the Mibu Village area of the Ashina Depths. She takes two Deathblows to kill but she’s actually pretty easy if you know what you’re doing, so you shouldn’t have too much trouble with this one.
From the Water Mill Sculptor’s Idol, run through the passage between the cliffs and into a clearing a short distance up the road. You’ll see O’Rin of the Water stood playing an instrument on the left, but she isn’t volatile yet. If you speak to her she’ll feed you a sob story about not knowing where Lord Sakuza is and not being able to get hold of him, and then she’ll ask you if you know where he is. When you tell her that you don’t know she’ll get annoyed and call you a liar, and then she’ll decide that she wants to kill you, which seems a bit drastic. You can forget the dialogue and just try to run past her, but you’ll still trigger the fight.
Once the fight has started there isn’t much to it other than Deflecting her attacks (which come thick and fast) and avoided her Perilous attack, but you can give yourself an extra advantage by using some Divine Confetti to increase the amount of damage you do to her – she is an apparition-type enemy, after all. If you’ve got some, use some Divine Confetti and start Deflecting her attacks, and you should get an opportunity to get your own hit in after she finishes each combo. O’Rin also performs a lunging attack where she moves backwards and then lunges forward and swipes her sword, but you can Step Dodge out of the way of this and then get your own hit in.
Other than that you just need to watch out for her Perilous/Red Kanji attack, which is a sweep of her sword. You’ll know this is coming because the end of her sword will gleam with light, so once you see this get ready to avoid the incoming attack. You have two options for avoiding this attack – you can jump and then jump again to perform a Jump Kick for some Posture damage, but I preferred to Step Dodge backwards out of the way and then get my own hit in to keep picking away at her Vitality.
Keep at these tactics of Deflecting her attacks, Dodging her Perilous attack and using Divine Confetti to boost your damage and you’ll soon open her up for the first Deathblow.
On to the next phase then and thankfully it’s no different from the first, so just repeat all of the tactics and you’ll open O’Rin up for the second and final Deathblow.
Killing her will reward you with some experience points and a Prayer Bead.