«Lambent Light» (ランベントライト, Ranbento Raito?) is a one-handed rapier owned by Asuna. Asuna's degree of proficiency with her sword is 1000 (mastered). Her rapier, combined with her speed, earned her the nickname «The Flash». Lisbeth boosted her weapon to +40. It is her end weapon used until the clearing of SAO.
It was first named in the side story Warmth of the Heart as a work done by Lisbeth, who stated it was of a quality she could only forge once every three months.
This was Asuna's last rapier in Sword Art Online which she continued to use it as her main weapon of choice until the fateful battle on the 75th Floor. Kirito used this rapier to stab and defeat Heathcliff in the final battle, thus clearing the game.