NulFrost negates one Ice-elemental attack or spell. Armors can be customized with SOS NulFrost, which will cast NulFrost when reaching critical HP status. It can also be bestowed by the NulFrost spell and via Rikku's mixes NulAll, Mega NulAll, Hyper NulAll and Ultra NulAll. The status is represented by a glowing light blue ball which orbits around the person it is affecting.
Barfrost is granted by the Synergist's Barfrost spell. It increases resistance against Ice-elemental attacks. It is also gained from the following accessories: Frostbane Brooch, Frostshield Earring. The status can be removed with Dispel and Dispelga.