Mark Peskin is a gigantic nerd, and proud of it, too. Like any successful geekazoid, the 34-year-old has parlayed his niche passion into getting paid. As DJ Apollynon, Peskin gets to combine his longstanding love affair with retro goth, industrial, and other doomy throwback genres at nightclubs and local fetish fetes with a particular yen for colorful cosplay. And he's just as old-school rivethead as the classic songs he's spinning. More than a decade ago, Apollynon dropped Covenant, Nitzer Ebb, and Sisters of Mercy while adorned in spikes, towering Doc Martens, and goofy goggles at the Nile Theater's and Boston's notorious industrial nights in 2000 and 2001. These days, however, his getups may be a bit more dork-oriented (read: Cobra Commander or a pink sex robot) but his sounds have remained just as sinister. Every Saturday, Apollynon and girlfriend, Sidney Slaughter (a.k.a. DJ Angel Toxin), crank out relentlessly gloomy audio at their popular City of Madness night at Club 24. And no one seems to bat an eyelash if he's wearing a unicorn mask at the time, probably because they're sporting some freaky-deaky duds themselves.