Asura

Asura (阿修羅) is the tentative name for the Raid Boss that governed the Tombstone Floor of the Great Tomb of Nazarick and fought with Ainz Ooal Gown during their raid to conquer the dungeon.

Appearance
The boss resembled a wrathful Nio statue of the fallen divinity "Asura." It stood five meters tall, with six arms, and his body is covered by an exquisite armor. On every one of his arms, he held a different weapon: a sword, an ax, a spear, a club and a bow and arrow on the last two.

Background
Asura was one of the five rulers of the Great Tomb of Nazarick that Ainz Ooal Gown had to beat in order to acquire control of the base dungeon. According to the Lord of Helheim's speech, he along with the other bosses are only released when players challenged them, with every one of them becoming stronger by the order of their release.

Overlord Prologue Arc
When Ainz Ooal Gown arrived at the entry point of the 1st Floor of Nazarick, his voice along with the other four rulers and the Lord of Helheim issued a challenge to the players invading their dungeon. They've stated that if the guild wanted to obtain control of the Great Tomb of Nazarick, they had to defeat them first.

Abilities and Powers
Asura was a "special ability" type Boss, possessing unique skills and spells that the players of YGGDRASIL weren't able to access. As the last of the bosses released from their seal, he was viewed as the strongest ruler that Ainz Ooal Gown had to beat in order to finally claim Nazarick. He boasted great power, resistance, life and defense and every one of its melee weapons had an elemental attribute that releases powerful attacks.

Active

 * Solar Flare: From its flaming sword, the boss generates a burst of fire targeting one enemy. The fire rises around the player ascending as a flame’s pillar.
 * Neptune Lightstorm: A super move activated from its cold ax. The attack generates a bluish-white orb of energy over the boss head that releases light beams over all the field. The attack generated cold elemental damage and put under a debuff of [Slow] at the targets hit.
 * Venus Monsoon: Using his gigantic club, the boss summons heavy clouds that release acid rain over its enemies.
 * Jupiter Tempest: Using his electric lance, the boss releases great strikes of lightning across the floor of its Coliseum.
 * Great Ore of Mercury: After using this buff resistance spell on himself, the boss reduced the DPS (Damage Per Second) that Warrior Takemikazuchi could inflict upon him to 1/10 of the previous amount.
 * Lunar Sword: Releases slashing shockwaves that tear throughout the air, striking both the sky and ground.
 * Saturn Meteor: The boss fires its arrow to the sky creating a black hole, and from there a massive storm of meteors descend over the field.
 * Summon Primal Elementals: After taking enough damage, Asura throws its five weapons towards the sky and calls four Level 87 Primal Elementals (Fire, Water, Earth & Air ) and a level 90 Primal Star Elemental. Each elemental takes the place of one of the boss weapons and act as its minions. However, while the respective elementals remain on the field, the boss will not be able to use his elemental weapons.

Trivia

 * Bukubukuchagama noted that some of its pattern's attacks were similar to the Meteoric Turtle, a raid boss that the former clan defeated before.
 * Asura was likely based on the "Asuras" of Hindu mythology who were power-seeking deities.
 * When Momonga wore the Robe of the Immortal Seeker, Yamaiko compared him to looking like an asura.

Quotes

 * (To Momonga's party): “Oh foolish ones who challenged us last, know the might of those who become stronger with every layer of binding removed from us.”
 * (To Momonga's party): “To think you have made it this far! It appears I have underestimated you! In that case! Come forth, my minions!”