User blog comment:IamJakuhoRaikoben/Chapter 405: Tartarus Arc: Part 6 - Magna Carta, Review./@comment-24734283-20141021190952

Hiro posted this on twitter

https://pbs.twimg.com/media/B0MiQ-iCAAAB4gh.jpg

Some think it's E.N.D. but if you read Rave Master than you should know who this is.

But maybe why Hiro's showing this is because maybe E.N.D. is going to be based on Lucia.

But that's my theory.