Torsions are an important element in Dissidia Final Fantasy Opera Omnia. As described in-story, they are tears in the fabric of space-time created by a force unknown.
The gods Materia and Spiritus created a new world at the behest of the Crystal in order to give respite to the warriors they had forced to battle in World B. The intended sanctuary was soon disrupted by dark rifts, known as Torsions. The Torsions not only release monsters over the landscape, they jeopardize the very fabric of the world, and potentially other worlds as well. The appearance of the Torsions is what prompts Mog to awaken and gather warriors.
Torsions appear in many places around the landscape and open in other worlds as well. Numerous individuals find themselves either caught in Torsions or travel through them on their own and emerge in the Crystal's world. These people have an attribute which Mog deems the "Light," and he recruits the majority of them on a journey to close the Torsions. However, there are dozens of Torsions scattered around the world, and they must be closed in accordance with the party's current level of strength. Clearing the smaller monsters in the area and defeating the large and powerful creatures that stand sentry at the Torsion's entrance is usually sufficient to close the rift.
In addition to the Torsions that apparently open at random, certain characters (such as Kuja and Kefka Palazzo) deliberately open Torsions. These Torsions usually connect one part of the landscape to another. The interior of a Torsion is filled with darkness, and those within find themselves unusually drained of energy.
It is later revealed that all individuals who appear in the new world, including the "Warriors of Light" recruited by Mog have the ability to open new Torsions rather than simply closing existing ones. This ability is itself what Mog had deemed the "Light." Vincent Valentine demonstrates this in Imber Manor when he creates a Torsion as an escape route for the party.
The party find a Torsion that is unusually large and energetic at the top of Utopia Niveus. When they fight Garland in front of it, the energies generated by their battle inflame the Torsion and call forth Dark Bahamut.
torsion refers to the act of twisting, turning, or otherwise rotating an object on an axis with torque applied to said object.In mechanical physics,
The Opera Omnia universe was "twisted" out of alignment when the first tears appeared, hence their name.