Bosses in Sekiro: Shadows Die Twice are special, powerful Enemies that do not respawn. Bosses are encountered throughout the game and feature special movesets, increased health, and unique mechanics. Some bosses may be optional, whilst others must be defeated to continue through the game. Most Bosses have several red markers next to their Vitality bar which must be removed before the Boss can be killed, each of which requires a Deathblow; a Boss' Vitality and Posture is fully restored in between Deathblows, and some Bosses can gain additional moves or abilities as each Deathblow marker is removed. Immediately after the final Deathblow marker is removed, a Boss must be finished off with a special Finisher Deathblow, which is performed like a regular Deathblow but involves Sekiro performing a special finisher animation unique to each boss.
The only way to remove these Deathblow markers is by completely depleting the Posture or Vitality of said Boss and then performing a deathblow. In general, Posture damage accrues far more quickly on humanoid bosses since they frequently Guard, while Vitality damage accrues far more quickly on more bestial bosses since they do not, but the enemy is rendered vulnerable to a Deathblow regardless of which one you deplete.
Since you can perform a Deathblow on a Boss even when it is at full health, and because Posture damage accrues quickly, it is generally advisable to focus on Posture damage in the vast majority of fights; that said, lowering a bosses health lowers its posture regeneration (see the Posture page for details), so you may still want to damage the boss - in fact, a few bosses require this. Accruing Posture damage generally requires you to repeatedly Deflect a boss's regular attacks, but because some attacks cannot be Deflected, you will have to learn to dodge them, either by using Step Dodge, Jumps, or even the Grappling Hook. Additionally, you can also deal significant Posture damage by performing the appropriate counter to Perilous Attacks (see that page for details). Blocked (not Deflected) attacks also deal moderate posture damage to the defender, so forcing a boss to block repeatedly can also slowly build Posture damage, though this is much slower than the above methods - but it can also accrue Vitality damage as well.
Boss arenas, when entered, generally block off the pathways to progression and/or retreat with a silvery mist, though selecting Quit Game from the pause menu will drop the player off in a safe area outside the boss arena and restart the fight, allowing the user to try again from the beginning (after resting at a Sculptor's Idol to replenish resurrection charges and consumables).
Bosses & Mini-Bosses
Mini-Bosses function almost identically to Bosses, as in they have one or more deathblow markers which must be removed, though they do not require the final Finisher Deathblow. The fights may also be dramatically easier due to their often simpler movesets, and some mini-boss battle arenas can be escaped mid-fight or skipped by walking around them. Mini-bosses are not counted towards the Trophy/Achievement for defeating all bosses.
All Sekiro Bosses Guide
A fearsome opponent riding a sturdy mount and brandishing a long-reaching polearm.
An old acquaintance and agile opponent, unmatched in speed and cunning.
A determined samurai who seeks to gain immortality through the Dragon Heritage.
Illusionary monkeys that can be defeated by taking advantage of their senses.
This colossal ape sits in its watering hole, tending to the Flower in order to attract a mate.
The immortal Headless Ape and its mate must be defeated to reach the depths of Ashina.
The nebulous monk watches over the cave entrance, deep in Mibu Village.
A master of the blade who is ready to cut down those who fall to Shura.
One of the greatest of the Shinobis, and Sekiro's father.
Eternal watcher of the Fountainhead Palace.
The Divine Dragon lies in wait in another realm.
The Owl in his prime will showcase his true powers.
He once asked Wolf to kill him when it came to this. Now is the time.
A master of both blade and spear. It will take all of Sekiro's skills to defeat him.
A general of the Ashina army; Kawarada is a nodachi-wielding samurai located near the Ashina Outskirts Wall - Gate Path Sculptor's Idol found in the Ashina Outskirts.
Men who have long since lost themselves to bloodlust and a deep hunger for violence, many of them needing to be imprisoned or bound to keep others safe. Their strength and fury, though indiscriminate, has been co-opted by both sides of the conflict between the Ashina clan and the Interior Ministry.
A general of the Ashina army; Yamauchi is a nodachi-wielding samurai located in the courtyard found slightly past the Outskirts Wall - Stairway Sculptor's Idol.
A skilled Shinobi hunter armed with a spear that is ready to pierce through any and all Shinobi it crosses its path with. He works as a mercenary with the bandits attacking the Hirata Estate.
A bull held within the gatehouse of Ashina Castle, with a bundle of burning tinder tied atop its horns. This bull cannot only ram its foes with immense force but also set them ablaze should they be foolish enough to take it head-on.
A general of the Ashina army; Matsumoto can be found giving an inspiring speech to his men on the steps leading up to Ashina Castle.
One of the Seven Ashina Spears: a group of samurai who were personally awarded their weapons for the integral role they played in the Coup planned by Isshin Ashina. Yamauchi can be found in loitering in front of the building where Sekiro first attempted to rescue the Divine Heir in the Ashina Reservoir.
Lone Shadows are the Interior Ministry's most trusted agents; the Longswordman is a man in search of a cowardly shinobi rumored to have sought refuge in a well after shamefully failing in his oath-bound duty.
A master of the Ashina Style developed by Isshin Ashina and his clan; he can be found in quiet meditation within the Dojo of Ashina Castle, every swipe of his blade seemingly striking twice in the same moment.
A headless apparition-type enemy that emits terror to anyone it crosses its path.
One of a pair of elite snipers stationed in the Gun Fort; Shirahagi belongs to the Snake Eyes: an elite group of women stationed able to pierce distant targets with their mighty flint cannons and phenomenal vision. She guards the Poison Pools located beneath the Gun Fort in the Sunken Valley, her time spent among the noxious fumes of the place having inured her to the ancient weakness of her ancestors.
A Elite enemy found at Ashina Depths: after the hidden forest Idol when heading to the left up some branches.
The one who strayed from the Buddha, entrancing the village in thick fog and illusions.
Lone Shadows are the Interior Ministry's most trusted agents; Vilehand, an accomplished swordsman and practitioner of poison-based martial arts, can be found accompanied by another nameless Long Shadow Shinobi in the Dojo of Ashina Castle after the Interior Ministry attempts to kidnap Kuro, the Divine Heir from the Ashina clan.
Lone Shadows are the Interior Ministry's most trusted agents; Masanaga and his trio of shinobi wolves can be found mourning the death of another Lone Shadow found within the Serpent Shrine of Ashina Castle. The group appears after the Interior Ministry attempts to kidnap Kuro, the Divine Heir from the Ashina clan.
A warrior clad in heavy platemail armor with no visible weak points; he seems to be guarding the only passage leading deeper into Senpou Temple, and wields a massive claymore in battle. He and his son Robert have come across the seas from the South in order to seek the Waters of Rejuvenation rumored to reside within Senpou.
One of a pair of elite snipers stationed in the Gun Fort; Shirahagi belongs to the Snake Eyes: an elite group of women stationed able to pierce distant targets with their mighty flint cannons and phenomenal vision. She guards the upper-most reaches of the Gun Fort from all that would threaten it, and can be found standing beneath a giant statue of the Buddhe located in a cavern slightly past the Ashina Depths Sculptor's Idol.
A giant bull Found at Fountainhead Temple area, by taking a left turn from the Flower Viewing Stage Sculptor's Idol.
One of the Seven Ashina Spears: a group of samurai who were personally awarded their weapons for the integral role they played in the Coup planned by Isshin Ashina. Oniwa can be found discussing plans to take back the castle with Genichiro and surviving members of his forces near the Ashina Reservoir Sculptor's Idol after the Interior Ministry enters their final phase of attack on Ashina Castle.
A master of the Ashina Style developed by Isshin Ashina and his clan; Mizuo can be found in the small dojo located underneath the room where the Tengu guarding Isshin Ashina once stood before the forces of the Interior Ministry began their final assault on Ashina Castle. His loyalty—or bloodlust—has driven him to the brink of madness.