Elucidator

The Elucidator is Kirito's black sword in Aincrad: a demonic sword dropped by the 50th-floor boss. It is not an Underworld weapon — no Priority, no Armament Full Control — but a SAO player's sword, heavy and above a netherite sword. It is carried on the back and drawn over the shoulder; with the Dark Repulser in the off hand, it unlocks Starburst Stream.

Getting the sword

No recipe or loot yet: the sword is in the Combat tab of the creative inventory, or given with /give @s slimeartonline:elucidator.

Stats

Its tooltip: "A demonic sword dropped on the 50th floor. Worn on the back: [R] draws it over the shoulder; both in the hotbar, [R] draws the two at once."

The back scabbard

While the Elucidator is in your hotbar or off hand, its scabbard sits on your back: alone, diagonally, the hilt above your right shoulder. With the Dark Repulser, the two scabbards cross in an X.

The details, including what happens to the item in your off hand, are on Scabbards and carrying weapons.

Starburst Stream

With the Elucidator in your main hand and the Dark Repulser in your off hand, press X (sword skill) or say "Starburst Stream", no System Call: sixteen strikes chained by alternating blades, in blue-white light. Each Elucidator strike deals 80% of its damage, the sixteenth 160%; 20 s cooldown. See Starburst Stream.

Tips

• Keep both swords in the hotbar: a single press of R is enough to go dual wield.
• The Elucidator has no Enhance Armament: speaking the art while holding it is refused ("Hold a Divine Object…").