The Sapphire Wand is more effective at long range than the Frost Shards, the Mage's second weapon. Also, since the projectile rips through several enemies at once, it is very effective against columns and huge mobs of enemies, such as crowds of ettins at the Hypostyle, or any corridor. It's also useful to preserve mana. Because the wand fires a "ripper" projectile, it cannot be reflected or deflected away. This, combined with its infinite ammo, make it highly effective against "deflector" enemies such as the Centaurs and the Heresiarch.