Being in the same class as someone means that you have attributes or qualities that are similar to them. The antonyms for this can be found in terms of being different, unique or diverse. Being different refers to qualities that are not alike, while uniqueness means having qualities that are only present in one individual. Being diverse signifies having a variety of attributes, ranging from cultural to personal differences, which makes one stand out from others. In essence, the antonyms for "being in the same class as" are all about standing out from the crowd and having unique features that make one distinct from others.