I just finished episode 1. From what I understood:
Renzu was invited, or I think forced by Mushi in human form to take part in the Mushi banquet where they said that they have been requested to offer her Kouki so that she transcends in to a Mushi.
Now the question here is if she would have drunk the whole Kouki (although that didn't end up happening because the banquet was interrupted) from the wine cup, how would she have conceived a child, let alone the prophesied grandson with unique powers.
This can only mean that that Mushi were deceiving her but that does not seem to be the case either. We see that after the banquet was interrupted, the human Renzu did have a grand child with unique powers.
So can anyone please make it clear for me about how Renzu could have had a grandchild, supposing she had drank the whole Kouki (as was probably intended by the Mushi).