"Yulia" and "Nova" could refer to characters from a manga, anime, or comic series. When combined with "cosplay," it's likely that you're looking for information on cosplay related to these characters, possibly from a series that has a significant following in the cosplay community.
Based on archived forum discussions (from cosplay galleries and early 2010s image boards), the three most praised images from Vol. 13 are: yulia+nova+cosplay+vol+13+top
: Rather than a 1:1 recreation of a specific anime or video game character, the "Top" in Vol. 13 serves as an interpretive piece. It allows the viewer to project various "tough-heroine" archetypes onto the costume. "Yulia" and "Nova" could refer to characters from