At some point, Rean brought out the vial of Half True Dragon Blood. As mentioned before, what mattered in this vial was the cultivation of the Half True Dragon. Otherwise, Kentucky's blood would probably be better. Rean used half of it on his new Black Star, increasing its power even further while still in Divine Low-level. One must remember that due to cultivation, neither the twins could wield weapons at the Divine Middle-level or higher. It would only become possible once they reached the Void Tempering Realm at the very least, and probably some stages further into that level.