The Wraithverge is a weapon from Hexen. Parias the Cleric uses this weapon. It is a staff (verge) whose visible part is a large, ornate cross with a large ruby on the end. Like the Quietus and Bloodscourge, the Wraithverge needs to be assembled from different segments found throughout the game.
The Wraithverge is the most destructive weapon in the game. When fired, it shoots a sphere of spiritual energy which splits into four ghosts (wraiths) that rend and tear at enemies that get in their way. Part of the usefulness of the ghosts is that they attack an enemy and then, once the enemy is dead, will seek out and attack another enemy until the ghosts' energy is used up and the ghosts disappear. Ghosts will attack any enemy in their line of sight, even if the enemy is not in the player's line of sight. This makes the Wraithverge particularly useful against large numbers of enemies.
The ghosts can, however, be turned against the player if they fire the Wraithverge at any monster that is in protect mode (the Heresiarch's reflective barrier, the Mage's Icon of the Defender, and Centaur/Slaughtaur in shield stance before the ghosts split from the original projectile) or if they are repelled with a Disc of Repulsion. It is thus wise to maintain a stock of Discs of Repulsion of your own, when unleashing Wraithverge on certain foes. Nevertheless, it is still quite useful against most enemies and bosses.
The Wraithverge is also the most mana-consuming weapon in the game, requiring 18 of each kind of mana.