Sekiro: Shadows Die Twice - GOTY Edition

So to get to this boss fight you will need to advance towards the 'Purification' ending, so here is a quick run-down on how to get here:

You cannot get this achievement in your current playthrough if you have already defeated the Divine Dragon before doing the below steps.

First, defeat Owl on the roof of Ashina Castle. Talk to Kuro inside, then hide behind a corner nearby and eavesdrop on Kuro and Emma. Rest, then speak to Emma and agree with her. Rest again, then head upstairs and speak to Emma again. Next, head to the Old Grave idol and enter the door next to the idol to talk to Emma again. Then head to the Dilapidated Temple and eavesdrop on Emma and the Sculptor from behind the building. Head inside and talk to Emma and choose the option to confront her. She will give you an item. Praying at the Buddha statue will then take you to a modified Hirata Estate.

Kill or run past the first mini-boss (to kill him kite him back towards the bridge and he won't attack you, then Whirlwind Slash him to death), then head in past the idol and you will have a rematch with Juzou the Drunkard. Take him down or not, then head in and through the building to find Owl in the room Lady Butterfly was in previously.

All that just to get to him. This boss is no slouch either, and is easily one of the toughest in the game. His moveset is very similar to his first fight, however there are some tweaks to his combos.

The main tactic here is to just deflect his attacks until he either hits the double shuriken followed by the overhead slam, or the sweep. The former is fairly rare, but if he does it dodge to the side to get behind him for some hits. The sweep is the easiest to bait. Whenever he does a combo and you see the red symbol, jump over the sweep and try and stay in front of him. He will try to go for a charged overhead slam. Dodge to the side just as he shouts and whack him from the back a couple times. Dodge too early and he will perform a very damaging spin attack. Those are the two attacks you are looking for him to do.

What you are looking to avoid is his firecrackers. He pulls these out at the back end of a combo if he doesn't do the sweep. As soon as you see these line the air you have two options. The first is to dodge backwards, which is the safest. Or you can try to dodge forward and to the right to get behind him. This is incredibly risky, but you can get multiple hits in. The other massively damaging attack is his thrust. He can either do this following firecrackers or not. Either way, you want to get out of the way unless you are comfortable with a fairly delayed Mikiri counter. If you mistime it, he will practically one shot you with a flying spin after it.

Into Phase Two, it is very similar to the first in every way but the literal Owl flying about. Father Owl will sometimes disappear. When he does this just run around for a bit because he will pop out of the flying Owl for a slam. The other new attack happens after the Owl lands on his arm. The Owl will turn fiery and fly at you, immediately followed by Father Owl performing his thrust. My advice is to stay away here, jump over the fire owl and let Father Owl thrust air. Otherwise the second phase is the same as the first. Whittle his health down when he launches his overheads, and eventually you should down him for that achievement.

If you are looking for a visual guide, here is a neat boss guide from Fextralife:

In this video guide I will show you how to defeat Great Shinobi - Owl at the Hirata Estate. Now to get this fight to come up you will need to do certain things first in order to get this achievement.

You will need to first beat Great Shinobi - Owl on top of Ashina Castle. From here talk to Kuro after the fight and exhaust his dialog. Then go behind the wall in the library and eavesdrop on him. You will then need to rest and speak with Emma, agree when prompt to. You will need to rest again, then speak to Emma again who has moved upstairs. You will then need to go to the Old Grave idol and speak with her in the cemetery. Next you will need to go to the Dilapidated Temple and go behind the building to eavesdrop on them.Go inside and talk to her and confront her about what you heard. She will give you another bell which will change the Hirata Estate.

You will need to do all of this before fighting the Divine Dragon or you will now get this achievement or get the aromatic flower. Which you will need to get the purification ending.

Now when you enter you will be about half way through it already. You will also need to fight a couple mini bosses before entering the same room you fought Lady Butterfly.

A few things I used in this fight are firecrackers (any type will do), divine confetti, and whirlwind slash.The divine confetti seems to do extra damage to him even though he is blocking so I decided to use it.

First Phase: Now this fight will be almost the same as when you fought him on top of Ashina Castle. With the exception of the firecrackers he uses and the shadowrush.

Your main attack points that you will need to hit to break his posture will be the shadowrush, and a multiple combo of hits followed up by a sweep attack. You will need to mikiri counter the shadowrush and when he does the sweep attack you will need to jump on top of him.

A few other points of attack are whenever he does his shuriken throws. He has two variants of these, one he will do a slash charge afterward. The second is he will do a jump slam attack. Now after both of these he will be vulnerable for a few hits.

Other than that he might do a slow overhead slam attack which is pretty slow and leaves him vulnerable for a hit.

If you think you have the timing down to when he throws down his firecrackers you can get behind him and get almost five hits on him before moving away. He has a couple of different types of attacks for these as well. One he will have a flurry of attacks and in the middle of it he will throw them. Otherwise he will just throw them in your face followed up by a shadowrush. During the second phase he will also throw them and then teleport away with the owl.

With all this in mind to know when to attack you will also need to keep pushing him by attacking him a few times to make him attack you back. You will also need to deflect his attacks as well so you can get his posture down. If you keep on him the whole time by attacking, deflecting, and making sure you counter the kanji properly you should be able to break his posture before getting his health down.

Second Phase: The only difference in the second phase is that he has two versions of an owl attack.

The first one is the owl will be blue and he will tend to teleport around the map. When he does this the safest bet is to just run round until you hear him do a slam behind you. If you are fast enough try to get a hit on him.

The other attack is the owl will turn red and it will come at you on fire. All you need to do is jump over it, but be careful because he will usually do a shadowrush right after. Make sure you mikiri counter it.

One other addition to this phase is when he jumps off you he will tend to throw shuriken, just make sure to deflect it.

If you keep on him like you did during the first phase and counter everything while pushing him with attacks, you should be able to break his posture here as well. Killing him for the achievement.