Doublecast (ConceptTopic, 7)

From Compile Worlds

Doublecast is just one of the more awesome skills a Red Mage can use. You get to cast two spells at one turn, making for some instant kill in one turn. Thing is, you have to use up the total of MP normally used for the spells. In certain games, though, if your Red Mage has Bloodprice and Doublecast, go abuse this skill to your heart's content, especially if you have awesome healing powers that you can use as the second spell to be able to ignore those annoying costs, making the Red Mage unfathomably awesome.

Also known as "Twincast" in some other Final Fantasy games. And definitely not to be confused for "twincest".