|Spoiler Alert: This article or section contains details about plotlines not covered in the anime. Do not proceed unless you wish to be spoiled. |
The Boss is over four meters in height, has a black muscle-filled body, two heads, four arms, and four glowing-red eyes. Compared to its lower body, its upper body is irregularly large. The Boss carries two battering ram-like hammers with its upper arms and two thick steel chains, capable of anchoring a cruiser to the floor, with its lower arms.
The Boss appears slow and dormant at the beginning of the battle, but becomes more and more berserk as its HP is decreased.
The Boss' attack patterns include swinging down its giant hammers, sweeping with its two steel chains in all directions and a charge with its head lowered. Once the Boss' health drops to the halfway point, it will start using a wide-range toxic breath attack and even starts using an 8-hit combo Sword Skill, utilizing its four weapons, once the Boss' health drops to the red zone. Occasionally, the Boss puts its four arms in front of its body to defend itself against attacks, being able to deflect all attacks in this stance.
If its hammers hit the ground, the Boss becomes immobile for 0.7 seconds. The Boss also has many openings from behind him, even though the chain attacks also sweep behind its back.
However, the Boss' main weak point is its neck which, if hit, forces the Boss to halt its attacks and curl up into a defensive position for five seconds. This was taken advantage of in the battle against it by the attacker jumping off the shield of another player for a boost and using a high-power Sword Skill to deal massive damage at the weak point.
An initial scouting battle with Boss was planned for gathering information on the Boss' attack patterns weaknesses, therefore there was no detailed strategy used for the first Boss Battle attempt (except for observing the boss even after death), after which the Sleeping Knights party was wiped out.
The two tanks of the Sleeping Knights, Jun and Tecchi were assigned to draw the Boss’ attention with their hate skills and handle the Boss’ hammer attacks, ignoring the chain attacks, while Nori and Talken were supposed to take the advantage of the Boss being paralyzed after its hammer attacks to perform powerful skills. Yuuki was supposed to stay behind the Boss to use charge-type Sword Skills to damage it via the many openings from behind the boss. The two supporting players, Siune and Asuna were supposed to support their part members by casting healing spells. Though during most Boss Battles the front tank players usually change after a maximum of 5 minutes to recover their mental strength and concentration, however, due to the party’s small size, Jun and Tecchi were forced to remain as tanks throughout the entire battle.
After the Boss' true weakness was discovered, Yuuki used Tecchi as a stepping board after a hammer attack to gain altitude to be able to use her Original Sword Skill: «Mother's Rosario», to deal a great amount of damage on the Boss’ weak point, defeating the Boss with the final strike of the OSS.