Hello Kedrych,
Depending your definition of semi hardcore, you might want to check out Circle of Justice on Defias Brotherhood. Aliance, social, HC raiding and some M+ groups. Very stable guild for yeard with players that join both in wow as some other games nowadays. Definately 18+.
Sorry for the short message, I was just about to get some sleep! You can see our message here: [A] Circle of Justice - Defias Brotherhood
Cheers!
Des (posting with some obscure alt for god knows why)