Dragon Force

Dragon Force (ドラゴンフォース, Doragon Fōsu) is a recurring Blue Magic spell.

Final Fantasy V
Although not a Blue Magic spell, the Mix command to combine a Dragon Fang with a Phoenix Down creates the item Dragon Defense, which raises Defense and Magic Defense, and grants Reflect.

Final Fantasy VII
Dragon Force is an Enemy Skill that increases the caster's Defense and Magic Defense by 50%, to a total of 100%, for a MP cost of 19. The effect is cumulative. It is learned only from Dark Dragon by manipulating it.

Final Fantasy Tactics Advance
Dragon Force increases the caster's, or an adjacent unit's, Weapon Attack and Magic Power for the duration of the battle. The Blue Mage job class can learn the spell from the Thundrake and costs 12 MP to use it. It is notable for being one of two Blue Magic spells that can be permanently missed, as Thundrakes become extinct after a point in the game, the other skill being Goblin Punch.

Final Fantasy Tactics A2: Grimoire of the Rift
Dragon Force is a Blue Magic that increases the caster's or target unit's Weapon Attack and Magick Attack. However, unlike in Final Fantasy Tactics Advance, Dragon Force now has a range of up to four spaces.