Source: Baldur's Gate - Descent into Avernus

Weapon (longsword), artifact (requires attunement)

Magic Weapon. The Blade of Avernus is a magic weapon that functions as a vorpal sword.

Random Properties. The sword has the following randomly determined properties, as described in chapter 7 of the Dungeon Master’s Guide:

  • 2 minor beneficial properties
  • 1 major beneficial property
  • 1 major detrimental property, which is suppressed while the sword is attuned to an archdevil

Ruler of Avernus. As an action, you can point this sword at one devil you can see within 60 feet of you. That devil must succeed on a DC 22 Charisma saving throw or be charmed by you for 1 hour. While charmed in this way, the devil follows your orders to the best of its ability. If you command the devil to do something it perceives as suicidal, the effect ends and you can no longer use this power of the sword against that devil.

Infernal Recall. As an action, you can use the sword to cast Word of Recall. Creatures transported by this spell appear in an unoccupied space within 30 feet of the current ruler of Avernus, or a sanctuary you designate if you rule Avernus.

Destroying the Sword. The sword can be destroyed by casting it into the River Styx or melting it down in the forge that created it.