Blue Rose Sword

The «Sword of Blue Rose» is a Priority Class 45 «Divine Instrument» sword found in the Mountain Range at the Edge. It was highly coveted by the knights in the Underworld.

Background
According to fairy tales, Bercouli (the founder of Rulid Village) tried to steal it from the white dragon who protected the «Human World» but was caught. However, he was forgiven for the crime.

Alicization Beginning
During Prologue I of Alicization Arc, the sword was found by Eugeo, Kirito, and Alice Schuberg, but, as it was extremely heavy, it was left in the cave.

4 UW years after the events of the Prologue I, Eugeo returns to the cave to retrieve the sword and uses his rest days to move the sword from the cave to the storage hut near the Gigas Cedar over the course of 3 months, moving it by several kilometers each time and hiding the sword in the forest at the end of each rest day. Once he successfully transports the sword to the hut, he stores it there with the Dragon Bone Axe.

6 UW years after the events of Prologue I, Eugeo shows it to Kirito, who attempts to use the sword to cut down the Gigas Cedar, but fails to do so due to his OC authority being too low at the time to use the sword properly. After the fight with the goblins at the Mountain Range at the Edge, their OC authority reached a level at which they are able to wield the sword properly and use Sword Skills with it, which they use to cut down the Gigas Cedar in several days. Afterwards, it became Eugeo's personal sword with Kirito occasionally borrowing it.

Alicization Running
After Eugeo and Kirito are accepted into the Master Sword Academy, Eugeo keeps this sword in the drawer underneath the novice trainee dorm bed, as the Academy rules only allow Academy issued wooden swords for group competitions and practical exams.

Near the end of the first year in the academy, Kirito wants to borrow the sword to be able to show his 4-hit Sword Skills to Solterina Celulute, but Eugeo reminds him that his own sword from the Gigas Cedar branch should have been completed by then. After this, Kirito no longer needs to borrow Eugeo's sword, as his own sword's Priority class rivals the Sword of the Blue Rose.

Alicization Turning
As before, Eugeo is unable to use the sword for group practices and practical exams due to the Academy rules, therefore, the sword is only drawn during its weekly maintenance. However, one day, when Teiza and Ronie are late to come clean their sempais' rooms and Eugeo finds out that Raios Antinous and Humbert Zizek plan to exercise their right as upper-class nobles to punish the girls by raping them, Eugeo uses the sword to stop the upper-class nobles and unintentionally cuts off Humbert's arm.

Trivia

 * Roses in UW are miraculous flowers that bear fruit with the most «Sacred Energy» and are not allowed to be planted by civilians, nobles or even emperors. Because of this, it's no wonder that such a rare and miraculous flower is being used as the sign of this Divine Instrument.