I last talked to Kuro on livejournal... I can't remember when, exactly, but I think it was sometime in 2010 or possibly after that, no later than 2011. And I know Quad9Dyne forums were still around ~2 years ago because I checked on it. I remember Kuro posted on the UFFSite forums occasionally around that time too.
No idea what's happened in between then and now, though, sorry. I'm a bad detective. Sometimes domain names expire and you just don't feel like keeping up with it anymore.