Long ago, before humankind existed. There was a war between the celestial beings. The war was so big that even the Gods took notice of it, the Gods choose thirteen celestial beings to stop the war.
The thirteen celestial beings succeeded in stopping the war and was named The Zodiac. The zodiac continue to ruling in the celestial world, even after the Earth was created, they continued ruling the celestial world and guiding the humankind.
Everything was great until Ophiuchus decided to rebel. He was furious that he was not recognised as a zodiac. He betrayed celestial world, and stole the infinity stone and disappeared in the cosmos.
During his travels, Ophiuchus fell in love with a human after rescuing her from death, he fell in love with her and impregnanted her. But the child was not going to make it because no celestial being can have a child with a human. Ophiuchus saw the sadness on his lover face , so he decided to sacrifice his own life and create a new soul for the child.
All his powers in memories where locked inside the child's heart. Even if Ophiuchus is no more, his soul still lives on within the girl.
On the other side of the universe. The zodiac were furious, because without the infinity stone the celestial world will crumble. They decided to send out their own heirs to look for it.
And that where our story begins a story.