The Abyss Watchers are a legion of troops that all wear the same outfit consisting of leather armor over chain mail, a long cloak, and distinctive, pointed helm that was their signature. They also have iron kneecaps due to their unique sword techniques.
All of them use a great sword and a crooked dagger. The dagger is not primarily used for offense, or even parrying, but instead as fulcrum for the Watchers to utilize their wild, unpredictable fighting style.
By the time the Ashen One encounters the Legion, they are mercilessly fighting one another, seemingly because some of the Watchers have gone mad.
The Abyss Watchers were the main component of the Undead Legion of Farron, a special fighting force formed to combat the threat of the Abyss. Taking inspiration from the Wolf Knight (Sir Artorias, the Abyss Walker), the Abyss Watchers themselves sought to utilize the techniques of Artorias, and partook of wolf blood to do so. Now equipped with the strength of Artorias, they became intensely strong and agile, fighting in a coordinated and sporadic pack akin to wolves.
Though they meant the highest good, they were somewhat radical in practice. If there was even a slight threat of the Abyss, the Watchers would go so far as to raze a country to the ground. Their distinct outfits, topped off with a tall pointed helm, became an ill omen for any who saw them. Their wolf blood fighting style was enhanced by the revolutionary use of an ultra greatsword modeled after Artorias' sword along with a crooked dagger, utilizing the dagger as a fulcrum for them to develop their own unique, wild flipping and scrambling maneuvers that were even more unpredictable and vicious than their predecessor. As such, they disdained the use of shields and preferred a constant offense, and Hawkwood-- eventually deserted the Legion in part because of the mockery he received for his shield.
Their wolf blood did more than enhance their bodies, but their very essence, for all those who partook in it were linked to the soul of Artorias himself. As such, instead of each body hosting distinct souls, all that partook the wolf blood share the one soul distributed between them.
Along with the actual Abyss Watchers, the complete Undead Legion consisted of two other levels. To assist them, the Abyss Watchers recruited acolytes, who provided support via medicine. At some point, they made a pact of uncertain terms with one of the Crystal Sages of the kingdom of Lothric, who agreed to come to their headquarters in Farron and train their acolytes in sorcerous arts. Due to the Legion's emphasis of speed over physical power, they asked the skilled sorcerer to develop unique variations of existing sorceries for the acolytes to use. Some of them were made by a xanthous scholar named Heysel, the daughter of the head acolyte, and refined even further than that.
Perhaps the most telling of their fall were the number of foot soldiers tasked with the covert disposal of corrupted members, as the Abyss would slowly alter them, so the "Followers" as they were called would be sent to execute them before they were transformed into creatures. Their primary technique was to surround the target, burning and stabbing them, and finishing them with honor by throwing a spear to kill them.
Eventually, the Watchers linked the Fire collectively and returned as Lords of Cinder. When they did this, the spirit of the Old Wolf of Farron formed the Watchdogs of Farron, and lead lost souls to protect Farron Keep from being intruded upon. This wolf, thin and unable to move, is thought by some to be the wolf whose blood was drawn upon. The reason why they did not take up the throne is not fully certain, but several factors offer clues to it.
Beneath their home in Farron Keep, the ruins of Carthus contained the spirit of Wolnir, who fell to the Abyss long ago. Though his Abyss was kept within a chalice through unknown mechanisms, the corruption is evident in the ruins and in regions nearby, such as Smouldering Lake. Nearby the keep is the Cathedral of the Deep, where a darkness beyond humanity was collected, and bad things occurred. Either one of the mentioned factors, or neither one of them or even perhaps both, could begin to damage Farron Keep.
With nothing to live for after the Abyss Watchers linked the flame, the Followers went hollow, roaming the land and eventually disappearing into the Painted World of Ariandel. Since there were none to execute the corrupt, the acolytes were slowly devolved by the Abyss, and Farron was consumed in a rotting bog. Once the Abyss Watchers woke, their home was corrupt and their mission unsuccessful. They either went mad or were corrupted by the Abyss without the Followers to execute them, both or perhaps neither, and were left fighting in an endless battle with their most powerful foe: each other.
- Black Hand Gotthard: His summon sign will appear before the stairs leading up to the boss arena.
- Londor Pale Shade: If the player has done Yoel of Londor's questline and met Yuria of Londor, the Londor Pale Shade can be summoned for the fight. His summon sign can be found near the Farron Keep Perimeter bonfire.
- Sirris of the Sunless Realms: If the player has given the Dreamchaser's Ashes to the Shrine Handmaid and then talked to Sirris afterward, she can be summoned for this fight. Her sign will be located to the left of the door leading into the boss arena.
- Yellowfinger Heysel: If the player has defeated Heysel when she invades the player either in Crucifixion Woods or Farron Keep, and then encountered Rosaria, Mother of Rebirth at the Cathedral of the Deep and deepened devotion to her covenant, Heysel can be summoned for this fight. Her sign can be found between the Keep Ruins bonfire and the door leading to the mausoleum, next to the ruined tower covered in Rotten Slugs.
Soul of the Blood of the Wolf
Cinders of a Lord
The fight consists of the player fighting a lone Abyss Watcher, who is present during the entire battle. More Abyss Watchers will awaken to join the battle as it progresses. These Watchers are much more fragile than the main Watcher, but they can still deal a considerable amount of damage, especially when multiple attack at once.
Every other Watcher that awakens, starting from the second, will be red-eyed and hostile toward other Watchers. They will never directly attack the player or each other, but can still hurt them, should they be caught in a swing. These Watchers can be used to the player's advantage, as they assist in dealing damage and taking aggro. As such, it may be a good idea to switch to a more defensive playstyle while the player waits for these Watchers to even out the odds.
The main Watcher, although carrying a greatsword, is extremely fast and dexterous. He is constantly jumping around and evading the players swings by doing so. He will also try to take an advantage by swinging his greatsword around the floor of the arena. Never let your guard down, each and every attack can take you by surprise.
Depleting the main Watcher's HP will trigger a cutscene, which shows the main Watcher absorbing power from the corpses around the arena. After this, the second phase of the battle commences.
At this point, the Watcher's sword will ignite, causing it to deal additional Fire damage and leaving trails in the floor that erupt into large pillars of flame. The Watcher himself will also take on an Embered appearance, revealing his true form as one of the Lords of Cinder.
The other Watchers no longer rise during the second phase, but the main Watcher is considerably more aggressive and powerful. The fight plays out in a similar fashion, but most of the Watcher's greatsword attacks are altered in some way. Killing the Watcher at this point will end the fight, but dying will reset it entirely, requiring the player to beat the first phase again.
- Can be parried and backstabbed in both phases of the encounter.
- The Watchers wake up based on a timer. Damage dealt has no effect on how many of them are active.
- All Watchers are instantly killed when the first phase of the fight is finished.
- The red-eyed Watchers are fully capable of finishing off the main Watcher. This has no direct effect on gameplay, however.
- If an enemy followed the player up to the fog door, it may attract the red-eyed Watcher's attention and he will keep trying to attack it for the rest of the first phase, rendering him unable to help against the other Watchers.
- The Abyss Watchers that resurrect in the first phase of the fight are actually the same two Watchers, they will come back to life on the spot where they were killed.
- After defeating the Watchers, the Undead Legion Set will become available for purchase with the Shrine Handmaid.
- Hawkwood the Deserter is a former member of the Abyss Watchers.
- From the description of their soul and the ability to create the Wolf Knight's Greatsword, it seems that the massive soul of the Undead Legion is a reincarnation of Artorias himself, as many souls have been known to eventually reincarnate.
- The design of the Abyss Watchers appears to be based on the Keeper of the Old Lords from Bloodborne.