Inner Isshin (心中の一心, Shinjū no Isshin) is a Boss in Sekiro: Shadows Die Twice. This Complete Inner Isshin Boss Guide gives you strategies on how to beat Inner Isshin easily, as well as tips, tricks and lore notes. This boss is a variation of Isshin, The Sword Saint (剣聖、葦名一心; Kensei Ashina Isshin; Sword Saint, Isshin Ashina) and is added to the Sekiro Free Update, Patch 1.05. This boss can only be encountered in the new feature, Gauntlets of Strength.
Bosses like Isshin are special, dangerous Enemies that feature a special display on-screen when defeated, such as "Immortality Severed" or "Shinobi Execution". You will need to perform multiple Deathblows on them in order to defeat them, and filling their Posture Gauge is the only way to accomplish this. However, decreasing their health will make it so their Posture Gauge depletes more slowly, assisting you in accomplishing this feat. See Isshin Ashina for the NPC version.
Inner Isshin Location
Where to find Inner Isshin in Sekiro?
Inner Isshin is the boss you'll encounter in the following Gauntlets:
Inner Isshin Rewards
What do you get from defeating Inner Isshin in Sekiro?
Completing the Gauntlet of Strength: Severance rewards the following:
Inner Isshin Boss Guide Strategies
Sekiro Inner Isshin Video Strategies
Sekiro Inner Isshin Strategy Writeup
Unlike Isshin Sword Saint, you do not have to fight Genichiro Way of Tomoe directly before Inner Isshin. Because you always fight this boss either in as a Reflection or in a Gauntlet of Strength, it is a good idea to liberally use even very rare consumables, because they return to your inventory after the fight. Ungo's Sugar is useful in the second phase on high difficulties, as the combos there are very dangerous and can easily kill you.
Isshin Phase 1: He will start a decent distance away from you. One of his first attacks will be his new huge AoE with the Black Mortal Blade. Shortly after he sheathes his blade, he will unleash a large sweeping attack around himself (this has tracking and will hit you even if you are in the air). A few moments later, another attack hits on the edges of the first one, possibly hitting you once more. One of his main attacks is a double slash with considerable distance. He will sheath his sword and it will flash white, then he will dash and double slash. Deflecting both attacks is an option however, you can run backwards and sprint to the side. Once he slashes he is open for a quick two hits. If you stand close to him as he sheathes his blade, he will instead slash at you and follow it up with a perilous sweeping attack. Unlike his basic form, he uses the sweeping attack regularly during the fight. His main slashes are a three to four hit combo, delaying between each hit. A thrust for an easy Mikiri counter, which will be telegraphed as he will end up in the thrust position before committing. Along with these attacks, he will do a long range wind attack, which can be dodge by running sideways as you can get a couple free hits on him this way as well. And a close range, full screen sweep, giving you just enough time to sprint backwards before it goes off. Once you get the deathblow in phase 1, he may continue to attack for a second before stomping the ground to begin phase 2.
Isshin Phase 2: Phase 2 is a massive difficulty increase from phase 1. Once he stomps the ground, he will do knockback damage, but not Vitality damage. Pulling a spear and swiping it in a tight circle around himself. If timed correctly, you maybe be able to get a hit or two in before he begins his assault. Along with the spear, he will have a short sword with him, along with a rapid fire gun. During this phase, he will keep the wind sweep attack, using it randomly throughout the fight. He will be consistently more aggressive, moving towards you if you make too large of a gap, firing the pistol if the gap gets too large. Making a large gap, you may be able to bait him into using a thrust that can easily be Mikiri countered. His new attack for this phase is a combo consisting of a perilous sweeping attack, immidiately followed by a slash that will hit you if you are in the air (but can still be deflected). He will follow up with either a thrust attack with huge range or a circular force attack that can be easily dodged. He will do large, heavy hitting overheads, usually one after another that can be deflected at the cost of heavy posture damage. Dodging sideways as he descends from the overhead, you can easily dodge the hit and get a few hits in yourself. After Isshin deflects one of your blows, sometimes he will jump backwards and make a sweep at you with his spear. Right as he does this, dodging into the attack (towards him) will allow you to get several hits on him as well. Be careful doing this, as he may do another overhead directly after. Dodging can keep distance, as much as he may spam the gun, is the easiest way to bait him into thrusting, easy overhead dodges, and breaking his posture overall. NOTE: Using the Loaded Umbrella will save you from taking ANY vitality or posture damage if you are struggling to dodge/deflect some of the perilous attacks (unless he is using lightning, which doesn't come until phase 3) AND Isshin will take considerable posture damage if you are using the umbrella to deflect!! You can use the umbrella to help cheese your way through if other means are not working for you. Deathblow on this phase will move him into phase 3.
Isshin Phase 3: Almost the same as phase 2, except he has three new attacks. One being a large swing, in which he covers his spear in lightening and swings it at you. You will want to get close when he does this and jump, as to deflect it directly back at him for big Vitality and posture damage, along with a flurry of free hits. His second attack will be similar to his phase 1 long range wind attack, the main difference is instead of it being vertical, it will be more of a distance slash attack. Third new attack will be adding lightning damage to his large overhead attacks. You can deflect the lightning, although the timing can be difficult. Strategy will be the same as his phase 2 fight. Bait out the Mikiri counter along with his lightning attack, and this phase should go smoother than phase 2. Upon giving him the final deathblow, do not miss the Mortal Blade deathblow, or you will have to go at his third phase again.
If you defeat the boss you will see the writing "IMMORTALITY SEVERED" upon the screen.
Sekiro Inner Isshin Attacks & Counters
|Charged Attack, Vertical Force Wave||Isshin puts his sword back into the sheath and readies a stance. A glint will show on the hilt. After a delay he will strike downward with his sword, launching a wave of force infront of him. After another short delay a second wave of force will be launched forward following the same path.||Deflect, then dodge second force wave. Waves can be deflected fully but will leak damage if blocked.|
|Ashina Cross||Isshin puts his sword into its sheath and after a short delay steps forward towards the player and makes two very quick slashes with his sword.||Dodge left as soon as you see a flash of light at his hand. If trying to avoid this attack entirely, be sure to run as far as possible.|
|Ashina Cross Cancel||If the player is very close to Isshin when he is readying "Ashina Cross" he will cancel the attack by quickly smacking the player with his sword, then following up with a perilous sweeping attack. He will also do this after the player repeatedly deflects his attacks.||Deflect the initial hit then jump and immediately start slashing, this gives you 2 or 3 hits. Do not stomp him, otherwise you lose this opportunity.|
|Ichimonji Double||Isshin will raise his blade in a ready stance and perform an Ichimonni double. If the player deflects the first hit Isshin will stagger, then immediately transition into "Charged Attack, Vertical Force Wave".||Since "Charged Attack, Vertical Force Wave" is far more difficult to deal with, it is best to simply dodge. Look carefully at his posture, he leans slightly forward before striking. Dodge to your right when you see this.|
|Distance Slash||If the player is far away from Isshin and/or uses an item Isshin quickly dash at the player and slash them.||Make sure that you are far enough away that you have time to react or that it simply cannot reach you.|
|Black Mortal Blade Disk||Isshin puts his sword back into the sheath and readies a stance. Black and white particles start drawing towards him. After this follows an undeflectable sweeping attack with tracking. Another attack hits on the outer edges of the first one.||Quickly sprint away to dodge the first disk, then sprint towards him to avoid the second, you can get 1 hit.|
|Charged Attack, Horizontal Force Wave||Isshin will sheath his sword and charge an attack. After a short delay he will quickly swing his sword in a spinning motion causing a large force wave in a circle around him.||Wait for a moment, then deflect as soon as Isshin begins to move his arm. Alternatively, you can instead sprint and then jump toward him, then jump again on his head. The Sakura Dance combat art can also be used.|
|Charged Attack, Double Projected Force.||Isshin will sheath his sword and charge an attack. After a short delay he will make two slashes in the player direction launching discs of force with each slash.||The discs will deal damage through your block in not deflected properly. The attack is easy to dodge and it is recommended you do so as deflecting the discs will not affect Isshin's posture.|
|Sweeping Attack Combo, Vertical Force Wave||The combo begins with a perilous sweeping attack, followed by a mid-air slash and a vertical force wave.||Jump over the sweep, deflect the slash and deflect or dodge through the force wave.|
|Sweeping Attack Combo, Thrust||The combo begins with a perilous sweeping attack, followed by a mid-air slash and a far-reaching thrust.||Jump over the sweep, deflect the slash and Mikiri counter the thrust attack.|
|Leaping Slam||When far away from Isshin and/or using an item Isshin will leap into the air and slam down with his spear. He will then follow up this attack with either a sword strike or he will pull out his gun and shoot at you.||Deflect the slam then counter attack. Regardless of what he does after the slam he will either get hit or block your attack.|
|Retreating Sweep||Isshin will leap backwards into the air and sweep in front of him with his spear. He usually does this after blocking/deflecting several of the player's attacks.||This attack comes out very quickly and is difficult to deflect. Deflect, or quickly dodge forward for a free hit.|
All attacks from phase 2
He will jump into the air and lightning will converge on him. He will then launch the lighting at the player with a sword swing.
|Jump into the air and use lighting reversal to redirect the attack at Isshin, this will stun him. Sakura Dance is also very useful here.|
Inner Isshin Lore
- The reason why this younger version of Isshin appears is due to Genichiro using the Black Mortal Blade on himself, as a sacrifice, to bring his grandfather back from the underworld. As described by the Black Scroll key item, the Black Mortal Blade: "is said to hold the power to open a gate to the underworld. It is through this power that it creates life."
- Why this younger version of Isshin chooses to fight you, rather than let you go, can be surmised in the dialogue right before the fight: Genichiro has used the blade to bind Isshin to his final wish, which is to bring glory to the Ashina Clan and win the war (by getting the blood of the Heir) where he could not.
Inner Isshin Notes & Trivia
- Voice Actor: Andre Sogliuzzo (English), Tetsuo Kanao (Japanese)
- The Japanese honorary title of Kensei (剣聖) is only given to a warrior of legendary skill in swordsmanship. The literal translation of kensei is "sword saint", which implies a higher degree of perfection and moral dimension than the more commonly used "sword master" (剣豪, kengo). The title is not to be confused with the term "swordsman" (剣士, kenshi).
Inner Isshin Image Gallery
[images go here]