User blog comment:Sinister 00/About 666/@comment-82.40.154.8-20140103231514

Maybe insteaded of splitting the soul and body he actually made Great red into the final seal. Maybe something since GR has been know to take action, like with Issei, maybe he agreed to be the final seal for 666 and thats why he move into the Demensional Gap. so that he could ensure that the seal would never be broken.

It would also explaon why Rizevem whats to kill him.

Also, if Issei had a part of 666 in him, it would have proably already have shown itself hs he has been in dozwens of life threating situations, and has died twice. not to mention that Issei has broken pretty much every seal on the Boosted gear's power so Ddraig would have sensed it by now, or at lest have a  hunch.

P.S. great Red is the final seal mya y not be the best choisce of words.