It was actually reasonable to assume that the spammer is Karl because Karl sometimes changes his post style in a drastic way. It is at least reasonable to assume that the spammer is a far right and he/she is either literally Karl or someone he knows.
^You intentionally pretended to be an inner city black dude not just once but actually twice. Your "upside down cat" alt is also clearly...you. Hence it is reasonable to believe that the new dude is probably you.