Vult was a Lord Inquisitor of the Ordo Malleus sometime in the 41st Millennium. A strict Amalathian, Vult attempted to oversee the eradication of Horusian ideologies within his order. He eventually rose to the position of Inquisitorial Representative on the Council of the High Lords of Terra.
While aiding Inquisitor Covenant in combating a heretical Inquisitor faction known as The Triumvirate, Vult sacrificed himself by holding off a tide of Daemons to allow Covenant and his retinue to escape.
Vult which in Latin is the third-person singular present active indicative of volō (wish, want) might be a reference to the Latin Catholic motto Deus vult which is particularly associated with the Crusades.