Precise astronomical measurements of the fine structure constant and universe expansion rate have revealed that they vary through specific directions, indicating an anisotropic universe. The curvature in complex spacetime can be interpreted as spatial warping evolution along with its travel through the imaginary time dimension. The complex spacetime worldlines of the universe spatial factor evolution through the imaginary time are utilised to model the universe anisotropy. The worldlines of a positively curved universe revealed both positive and negative solutions, which imply that matter and antimatter could be evolving in opposite directions as distinct universe sides, theoretically corroborating the axis of the cosmic microwave background and observed anisotropy. The model indicates that a nascent hyperbolic expansion is followed by a first phase of decelerating spatial expansion during the first 9 Gyr, and then, a second phase of accelerating expansion. The model potentially resolves the tension in Hubble parameter measurements, with a predicted density at the phase transition of 1.12>1. In addition, it predicts a final time-reversal phase of rapid spatial contraction leading to the Big Crunch, signalling a cyclic universe. On spacetime duality, the simulations of the spacetime continuum flux through its travel along with its predicted worldlines demonstrated the fast-orbital speed of stars resulting from an external momentum exerted on galaxies via the spatial curvature through the imaginary time dimension. These findings indicate that antimatter can exist as a distinct side, which influences the evolution of the universe; physically explaining the effects attributed to dark matter and dark energy.