Aster started inspecting his body to find out what was happening and he saw that the gray mist was being condensed on his dantian, he focused on it and then he saw that besides the earth core that was formed when he broke through there was a black book with golden decorations which was absorbing that grey mist he saw coming out of Isaac.
He supposed this book was the result of Aldebaran's evolution but to make sure he decided to speak with Rya.
"Rya, can you come here?".
Rya stood up from her sitting position on the top of the golden sword in the mind space and she appeared besides Aster's earth core.
"Wow, those two are surely worthy of being chosen by Aldebaran… the evolution is not completed yet but this book is already something outstanding, if I'm not mistaken this thing has become some sort of cultivation manual but I don't know which rank will have once it is finished".