Board Thread:Wiki Discussions/@comment-25134516-20140703093231/@comment-1512913-20140703142914

Just because it's based on x concept doesn't mean it's a copy-paste of it. The thing is that we were told that only chakras of Ashura and Indra go on, not their souls. If it were souls, then it would be impossible for Hashirama and Naruto, Madara and Sasuke to be there at once.

Not to mention we were told that once one incarnate dies, the chakra goes to a successor. That means Madara had no longer Indra and Ashura's chakras when he got revived, this may explain why his eye crumbled.