In the distant past, the Guardian of the Milky Way galaxy named Lanancuras began to harbor a desire for more power. Because of his connection to the galaxy, he was able to absorb parts of planets and add them to his strength. As a result, he began invading the worlds he was assigned to protect. In the wake of his destruction, a following of creatures from across the galaxy pledged allegiance to Lanancuras and became known as the Kadrians. Taking notice of his ever-growing power and followers, the other Celestial Guardians confronted him; however, he had become too powerful, and they were defeated. Unable to subdue Lanancuras, the Celestial Guardians each gave up a part of their power and combined it into a single new Guardian, Mushra. In a final desperate attempt, they used Mushra's core by transforming it into a powerful card with which to seal Lanancuras in a prison. The prison was created from the remains of planets that had suffered under Lanancuras' tyranny. Because planets are themselves large beings, their combined strength- along with the power of the card- was able to restrain him. Thus Lanancuras was successfully sealed in a large meteorite.
The meteorite was sent off into the galaxy to be sealed forever. Meanwhile, the way Lanancuras had increased his strength had consequences on the planets of the Milky Way. On Earth, around the 22nd century, it was in the shape of a virus that merged with human DNA and destroyed the humans that way. In order to eliminate the virus, scientists worked on combining human DNA with the DNA of animals and other creatures immune to the effects. They succeeded and created a sentient race known as Enterrans (a race of engineered Earthlings) which are based on humans, insects, reptiles, birds, sea creatures, wild beasts, and phantom beasts. Eventually, a cure was found and the human race survived.
However, due to Lanancuras' influence, the Enterrans fought their human creators as well as the humans robotic creations, driving the human race to a near extinction state. Luckily, a scientist named Dr. Daigo Tatsuro placed his 4-year-old daughter Yakumo in a sleep chamber in hopes that she would save the human race and find the human sanctuary Shinzo and bring peace back to Earth which was then renamed to Enterra. When the meteor that Lanancuras was imprisoned in struck Earth during the earlier parts of the Human-Enterran War, it's fragment had struck an infant Yakumo giving her abilities that she would later discover.