OVA
Description
The Demon Beasts are an ancient extraterrestrial species originating on Earth millions of years ago. Forced to migrate to the planet Quasar PHL-5200 when Earth's atmosphere became incompatible with their biology, they retained ambitions of returning to dominate their former home. This species features anthropomorphic giant forms capable of generating tentacles and possesses shape-shifting abilities, enabling them to assume human disguises for stealthy infiltration. Their primary objective involves creating human-alien hybrids adapted to Earth's current atmosphere, establishing proxy rule.

A key figure, The Vanguard, serves as an advance scout sent to Earth to initiate hybridization. It targets biologically compatible human females, specifically Kayo Asakura due to her exceptional physiological suitability. Impregnating her results in a hybrid offspring. This offspring undergoes rapid maturation from infancy to adulthood within hours, wielding heightened intelligence and strategic capabilities. It launches the invasion by converting human females like Miki and Miyuki into mutated minions. The hybrid also exhibits telepathic abilities, forming a potent psychic link with Kayo. This link draws it back to Earth across dimensions and fuels its campaign of violence and domination.

Following physical defeat, the Demon Beast's influence persists through resurrection efforts orchestrated by followers. Cultists, including Miyuki possessed by the hybrid's essence, seek to revive the entity. Minions such as "The Mailman" and "The Slave" assist in these endeavors, including attempts to recapture Kayo, whose connection remains vital for resurgence. These efforts demonstrate the species' capacity for indirect manipulation and exploitation of human agents.

The species exhibits parasitic and mind-controlling traits, capable of possessing humans like Miyuki to further their goals. Their reproductive cycle relies on forced hybridization. Strategic methods include infiltration, psychological manipulation via psychic bonds, and the creation of subordinate mutants to wage invasion.