Well, from what I understood, Ashura was reborn 
as female (considering in the last volume she has 
breasts ^^), and Kujaku keeps referring to her 
as "kanojyo", which indicates female ^^ Yes, 
there is a strange father-daughter relationship 
going on, but that actually carries over from 
their pasts, and the cannobalism is from the 
Hindu scriptures itself..believe it or not, 
people, RG Veda is all taken from Hindu 
texts...everything that happens is something in 
their holy scriptures. Just CLAMP-ized.