Hiya! My lovely Mithra parnter is a level 20 Black Mage on Fenrir and she uses a Misery Staff that has Additional Effect: Curse. When we fight its nice to know the monsters can be cursed too! But don't be fooled, it doesnt last as long as the spell... but it does help. The length of her curse and how often its triggered seems to be going up with her staff skill
Here's the bookwork on it, >^.~< : http://ffxi.allakhazam.com/db/item.html?fitem=1995