Board Thread:Questions and Answers/@comment-27524978-20160114233341/@comment-5007517-20160514192936

To everyone saying that Flowey needed monster souls to become Asriel again, that isn't the case and it seems that you missed something. Flowey needed the power 7 human souls. This is supported by the quote, "Through your seventh and final soul, I will become God." In the library, there is a book that says something along the lines of, "It would take the souls of nearly every monster to equal the power of one human soul." So, the 6 human souls, plus the souls of every monster (except Napstablook) was equivallent to the 7 human souls Flowey needed to become himself again.