This spell was seen once used by Dumbledore in the Ministry of Magic, during the Battle of the Department of Mysteries on 18 June 1996, while he duels with Voldemort. This spell was told to be very powerful since when Dumbledore cast it, Voldemort couldn't bear the power of it so he conjured a silver shield to deflect it. When the spell hit the shield, 'a deep, gong-like note reverberated from it-an oddly chilling sound'. Although the spell is powerful, it didn't cause any visible damage to the shield, proving that the shield's power is at least equal to that of Dumbledore's spell. Apparently, this spell is not fatal, as after it was cast Voldemort taunted Dumbledore over his apparent reluctance to kill him.