Warning Spoiler Alert: This article or section contains details about plotlines not covered in the anime. Do not proceed unless you wish to be spoiled.

Ruthless Warder Chief (ルースレス・ワーダーチーフ(冷酷な獄吏長), Rūsuresu Wādā Chīfu?) was the mid-boss that impeded travel between the 23rd and 24th floors of the Labyrinth Tower on the 40th Floor of Aincrad in Sword Art Online. The boss had two Hit Point (HP) bars.[1]


Ruthless Warder Chief Full Appearance - OS manga Extra Chapter 2

The Ruthless Warder Chief was a massive, humanoid-type jailer monster with dark red skin, bizarrely large and long arms, and muddy yellow eyes, shining through a steel mask. Its main weapon consisted of huge metal rods with countless thorns.[1]

Attack PatternsEdit

The Warder Chief's attacks were mostly simple, consisting of brandishing its metal rod with all its might; however, the boss was capable of using Sword Skills. The monster's main attacks could be divided into two categories: narrow-range and wide-range horizontal swings. The former would only affect players tanking the monster, while the latter posed a threat to other members of the party dealing with the boss as well, since the attack would reach from one edge of the dungeon's narrow passageway to the other, thus making it impossible to dodge the attack.[1]

Like other jailer monsters of the 40th Floor, the boss possessed a troublesome algorithm known as «Bullying». This trait allowed the monster to ignore the usual hate value acquired by the players and instead prioritise assaulting players who had collapsed and could not move, or those who had suffered a debuff.[1]

Weak PointEdit

The Ruthless Warder Chief's weak point was its knees.[1]

Boss BattleEdit


The only known preparations for the boss fight were the months of special practice taken by the members of the «Knights of the Blood» in order to be capable of producing a sufficiently long break in battle for a «Party Switch».[1]


The raid party for the battle consisted of twelve players from the «Knights of the Blood» guild. The players were divided into two parties:[1]

  • Team B - Asuna as the leader,[2] Segro and Muldar as the tanks, a mace user Fultz, a cross-spear user Sanza and a one-handed sword user Nautilus.[1]
  • Team C - Uzala as the leader[2] and five more members.[1]

The strategy used by the raid party was for all the members in a team to combine their Sword Skills against the enemy's full swing in order to greatly stagger the Warder Chief, leaving him open to attacks on its weak point, the knees.


  • On October 15, 2023: The raid party engages the Ruthless Warder Chief.
  • After twenty minutes of battle, the raid party prepares to execute their next «Switch».
  • Team C successfully staggers the boss after parrying its attack. Asuna attacks the boss's knees with her «Triangular».
  • The Warder Chief's first HP bar is depleted. Team B proceeds to surround the Warder Chief.
  • Due to Nautilus absence from his position on the left side of the monster, Sanza is knocked to the ground by the Warder Chief.
  • Kirito joins the fight, saving Sanza by parrying the boss's Sword Skill with a regular sword slash.
  • With Kirito's help, the raid party quickly depletes the Ruthless Warder Chief's last HP bar.


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