User blog comment:Zathronas/Analysis by an author: Volume 2 episode 2/@comment-10380701-20140801011106

X-Ray and Vav actually. And it's not an x-rated comic, but the alter egos of Gavin Free and Ray Narvaez Jr. The same comic popped up in episode 1, with Mercury reading it.

Looks like it's pretty popular, actually.