Curse is a Status Effect introduced in Yggdra Union.
In Yggdra Union, Curse slows down the afflicted unit, greatly handicapping their battle performance. In addition, it anchors the unit so that they may only move one space per turn. The card skill Gravity Chaos inflicts Curse; units ailed by it are highlighted in indigo.
Curse reappears as an ailment in Gungnir. When Curse is in effect, HP recovery is not permitted for its victim and they will not be able to activate passive actions.