The meaning of "衰哥"is not "帅哥”."衰" is similar to " 帅 "in pronunciation.But the meaning of "衰哥" is the opposite meaning of " 帅哥". This is a pun in the borrowing.
when we are saying "这人太衰了“ we mean the guy is unkempt,dowdy,slovenly in apperance or especially " 衰" refer to his mess and abominable mettle/ temperament when someone is in bad luck. “衰人一个”is the very bad estimation to someone.If you are a 衰人,you cann't get a good girlfriend, you cann't get promoted, or even your friends will abandon you, etc.
It's usually used to tease or ridicule or jeer at someone.