Zone Nu "Genesis" is the Stage 5C of G-Darius, it is a bizarre extra-dimensional space that seems to even be outside the usual laws of time. It is from here that the the Thiima Spacetime Continuum actually spawned where a little prism can be seen during the stage. This zone splits in Area Y and Area Z.
Area Y: takes the players leads to distinct portions of the space
Area Z: same as Area Y, but with a double helix/DNA motif.
The revealed final boss here is The Embryon (Sea Angel).
Boss Battle
See "The Embryon" article for more information
Ending
As The Embryon explodes to his death, both Silver Hawks are escaping from the blast, however they are destroyed due to the collapse of the Thiima Spacetime Continuum, Both Sameluck and Lutia are floating in the collapsing void, disintegrating as they get closer to each other, sharing their first and last kiss before they phase out of existence, then a solar eclipse caused by Darius can be seen and then the camera shows the oceans of Darius, submerging in the depths as the credits roll.
Darius Odyssey Explanation
The destructive powers of the All-Nothing powered engines of the Silver Hawks destabilizes and react with the creative powers of The Embryon. Lutia and Sameluck are destroyed, but they're resurrected together as planet Darius. This ending is called "The Creation of Planet Darius".