Surtr

Surtr (スター, Sutā) is a Humanoid type, Evil God-class boss monster, and the final opponent in Muspelheim, along with his consort, Sinmara. Defeating Surtr would complete one of the parts of the Ragnarök quest, which is the Revenge of Bifröst Quest.

Appearance
Surtr is a jötunn, a humanoid giant who is at least fifteen meters tall, possessing ashen skin. In comparison to Thrym, Surtr has a younger appearance, with black hair and sharp horns protruding from the sides of his head. His eyes are the color of flames, and cracks filled with magma traces down all over his body. His only armor is the ones he wears on his legs.

His main weapon is a large wide-bladed sword of flame.

Background
Surtr was one of the Non-Player Characters (NPCs) created by the Cardinal System's «Automatic Quest Generation Function», thus the character was based on the Nordic legend of Surtr while the created character possessed a much higher degree of intelligence than usual NPCs as the NPC's core programming is connected to the language engine module, thus, instead of having a scripted response routine, he is able to change his speech according to the situation to some extent. Because of this, he is much more realistic than usual NPCs.

Mythology
In the original legends, Surtr was the king of Eldjötnar, or the fire giants, denizens of Muspelheim. He will declare battle against the major god Freyr, and engulf every land in the flames that he shall bring forth.

Also, the fire giants were the ones responsible in breaking Bifröst, thus marking the beginning of Ragnarök.

Setting
Upon the terrible news of the breaking of the rainbow bridge, Bifröst, faeries of every race feared that Ragnarok might really become a reality, deleting every player's data and forcing them to return from where they all had begun. Fire giants begin to infiltrate the peaceful realms of Alfheim and Jotunheimr, burning everything in their wake with Yggdrasill and Asgard as their main target. To stop the apocalypse from happening, faeries of different parties venture into the magmatic undergrounds of Muspelheim to defeat the ruler of the fire giants, Surtr, before he marches out of his realm and turn the World Tree to nothing but ashes.

Sword Art Online: Project Ragnarok
Surtr appears as one of the main antagonists of the series, ruling the underground, volcanic caverns of Muspelheim. He had been challenged by various group of faeries, including a team from the Knights of Round. The flaming wide sword he swings around is quite difficult to avoid, rendering many attempts in defeating him unsuccessful.

Gwenhwyfar's party, advantageous due to Helios' Blessing and battle information received from Merlin

Known Challengers

 * Gwenhwyfar's party
 * Tsukiyomi
 * Lancelot
 * Laevateinn
 * Miki (Undine)
 * Yuuto (Gnome)
 * Mondschein (Imp)
 * Kirito's party (defeated after failing to evade Surtr's Scorching Surge)
 * Asuna
 * Leafa
 * Sinon
 * Lisbeth
 * Silica
 * Klein
 * Various other parties