I remember seeing the chrono vortex for the first time in RA1 Retaliation on PS1 around 1999. On PS1 it looked more like a black/rainbow cloud that moves around a certain area in the map, I didn't know what it was or how it was generated since I didn't have internet connection. Today I know the story and tried to generate it.
According to the C&C Wiki:
A chrono vortex is an unfortunate side effect of the use of Chronosphere technology during the Second World War. A chrono vortex is essentially a rift in the space-time continuum that rampages through the battlefield, destroying everything in its path. It appears as a giant whirlpool of bending time, defying the laws of physics. This devasta...