According to simulations run on different futures of Ignis and humanity, Revolver says that Lightning's is the only one that leads to mutual destruction.
When two soaring, heroic 
roars merge into thunder,
Wenn sich das heldenhafte, tosende Gebrüll
der beiden zu einem Donnergrollen vereint,
Cuando los dos truenos se mezclan,
Quando os dois urros heroicos
voam e se unem ao trovão,