Ruthless Warder Chief

Ruthless Warder Chief (ルースレス・ワーダーチーフ) 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 HP bars.

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

Attack Patterns
The Warder Chief's attacks consisted in brandishing its metal rod with all its might, using narrow-range attacks and wide-range horizontal swing attacks, while also being able to use Sword Skills. Like other jailer monsters of the 40th Floor, the boss had a troublesome algorithm known as «Bullying», which was a trait of ignoring the usual hate value and aiming for players who had collapsed and couldn't move or who had suffered a debuff.

Weak Point
The Ruthless Warder Chief's weak point was its knees.

Preparations
The only known preparations for the boss fight were the months of special practice in order to prepare to create a sufficiently long break for a «Party Switch».

Strategy
The raid party for the battle consisted of twelve players from the «Knights of the Blood» guild. The players were divided into two parties: The strategy used by the raid party was to create a knockback, due to all the members combining 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.
 * Team B - Asuna as the leader, Segro and Muldar as the tanks, a mace user Fultz, a cross-spear user Sanza and a one-handed sword user Nautilus.
 * Team C - Uzala as the leader and five more members.

Summary

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

Trivia

 * Despite the boss' simple attack pattern, the power of even a single blow of it was large, being able to repel six players nearly five meters backwards, making it extremely dangerous for players to get in close.