The corrupted bounty hunter.

Samus aran a world class bounty hunter has just gotten her latest assignment from the galactic federation, to hunt down a "Rouge" member of the federation.

When Samus finds the rouge member she discovers he was a altered captured soldier, unfortunately for both of them he has not only Metroid DNA much like Samus, but he was experimented on with the X-parasite and with phazon to create the ultimate breeding machine to make more metroids and phazon creature.

When Samus gets closer to him she realizes its to late, his aura makes any female who comes near him want to breed, and he being near a female must breed.

Eventually Samus loses herself going from the bounty hunter known galaxy over to Dark Samus: breeding ground for Metroid/Phazon hybrids.