Elucidator

«Elucidator» is Kirito's primary sword in Sword Art Online. His level of proficiency with Elucidator is one thousand (mastered). This sword is a demonic monster drop and he wields this sword along with «Dark Repulser». It was boosted to +40 by Lisbeth out of a maximum of 50.

Elucidator was a boss drop from Floor 50.

Warmth of the Heart (Aincrad 48th Floor, June 2024)
First introduced when Lisbeth checked its name, to find it was not a player made weapon but a drop, and Kirito requested a blade of equal quality. It was then used to test the strength of Lisbeth's best sword, which broke upon striking Elucidator.