Nova: Omega is the story of Hitori Seishin, a mercenary on the planet of Esper. He leads Omega team in the Nova Mercenary Academy, and is the son of the legendary warrior Maia Seishin, now deceased.

He is in the final days of his education at the elite Academy, where at the last minute he's assigned a new teammate, Elvira. She is a total novice, but her unique abilities make her a promising addition to his team. We join the pair on their journey, Hitori, fighting to prove he belongs amongst the ranks of warriors indisputably his better, and Elvira, struggling to adapt to a world where the trophy for second place is a tombstone.

Meanwhile, ancient and powerful forces clash in the shadows, racing across the globe to secure powerful artifacts capable of upending the foundations of the world.

The mystery tag is there for a reason. There is intentional ambiguity in places (there is also some unintentional ambiguity and under-explained concepts).