Calibur


 * This page is about the whole Caliber story. You maybe looking for the Caliber quest, the Excaliber sword, the novel story or the alternative Caliber SS non-canon side story.

Caliber (キャリバー) is a side story in the Sword Art Online series that takes place in-between the Phantom Bullet and Alicization arcs.

Introduction
On December 28, 2025; Kirigaya Suguha (Leafa) showed her cousin, Kirigaya Kazuto (Kirito), a news article that the Holy Sword Excaliber in ALfheim Online (ALO) had been found. Excaliber was the rarest and most powerful sword in ALO, but, although Kazuto had Suguha had found the sword nearly a year ago, they were not able to break through the guardians of the dungeon that the sword was held in, until they ended up temporarily forgetting about the sword due to more important matters. However, Kazuto was then told that the weapon had only been discovered so far, but not yet acquired. Thus Kazuto called Asuna, Lisbeth, Silica, Klein and Sinon to form a full party and attempt to clear the dungeon again. However, after they arrived at Jötunheimr and got on Tonkii's back, they discovered that the other players discovered the location of the item via a quest that required slaughtering the beast-type Evil Gods. The group was then approached by an NPC named Urðr, who informed them that the slaughter was requested by the king of the frost giant tribe, Thrym, who had promised Excaliber as the reward for the help. However, unbeknownst to players, he needed to massacre the beasts in order to break Urðr's protection that prevented him from invading the land of the fairies, Alfheim, and causing a cataclysmic event known as Ragnarok. Urðr then requested for the fairies to retrieve Excaliber from the bottom of Thrym castle, Thrymheim, before the last beast-type Evil God was killed, as once the sword was removed, Yggdrasil would be able to grow its roots back into the Great Void, restoring its blessings to the world and causing Thrymheim to melt.