ぐちゃ is the SFX used when something soft got smashed, in this case likely his balls. Poor dude.

The premise of this comic kind of reminds me of Commander Shepard's line in the original Mass Effect about the cops moonlighting as corporate security. "If they're working under the table, they're mercenaries. I can kill mercenaries."

Also, it's always nice to see Meiling given an opportunity to succeed. RIP, random mooks.