The Pikachu ears and dog paw eyes help make Chung "cute" to the fangirls. We all know girls like "cute" things. Pikachu and Jigglypuff helped get girls into a franchise that's all about government (Err, I think there's a government in there somewhere. Hard to tell when teenagers are the ones destroying the criminal organizations.) sanctioned cockfights.
Rune Slayer has a kind of girlish appearance, aka the "pretty boy" look that most fangirls seem to be into these days.
Reckless Fist is your traditional "bad boy", not as popular as "cute" or "pretty" boys these days. (On the internet, at least.)