Valkyrie Seraph

Two sisters, born in separate worlds, and chosen by the Yin & Yang to be the core balance of the multiverse. Raised in a cruel and unforgiving world they struggle for survival against an unknown species that invaded Earth to destroy humankind. The Kamiya family, blessed with great power, are the only humans that can fight back against the aliens. Will they be enough to prevent mankind's extinction? Overtime the sisters get chosen by the Yin & Yang but are separated due to the aliens assault on their city. One creates a universe and the other is manipulated, how can they keep the balance when one is fated to kill the other.