Graviga

Quarter, also known as Graviga is a recurring spell from the series.

Final Fantasy V
Reduces roughly 3/4 HP of target. There is also a blue magic version called Level4 Quarter.

Final Fantasy VI
It is called Quartr, affects the entire enemy party, and reduces their HP by 3/4.

Final Fantasy VII
Demi3 reduces one target's health by 3/4 their current HP.

Final Fantasy XII
In FFXII, Graviga is an Arcane Magick and reduces the health of an enemy by 1/2.

Final Fantasy Tactics
Demi2 reduces HP by 3/4. This spell is very effective against the Lucavi bosses due to them having no gravity defense and high HP totals.

Final Fantasy Tactics Advance
Quarter reduces HP by 1/4.