Comic-Con remains the epicenter of nerdom, and nerdom has become big business in the years since legions of costumed fans first descended on San Diego.

CNBC caught up with several cosplayers at Comic-Con on Thursday and Friday, asking them about the pressing trends affecting the comic book and video game Mecca. How do they feel about big brands such as Uber and television networks establishing big presences at the once-niche event? What about the changing gender and ethnicity of storied comic characters such as Thor and Captain America?