I had a hen that attacks everyone except me. She bit their toes if they wore sandles lol. That was nearly a year ago. I did rehome her, but not because of that.
Right now I have a silkie rooster that I raised up from a chick and he's the nicest boy ever. But for some reason he recently started to hate my 6 year old brother. He flies at him and attacks him. It's not really a problem for us since I'm usually the only person that goes in the chicken pen.
The only suggestion I have is maybe try hugging him every time he attacks. You mentioned that he doesn't attack you so maybe the person he attacks should hug him and hold him for a little bit. I've heard it helps roosters learn their place.