You who think that is "The Patner" ?
To me it is Darksied and let me explain why
1st clue - Was in season 1, episode 9. When Psimon report to The Light, Queen Bee said that Boom tube test for new patner was a sucess and that he would bring more powerfull tecnology to earth that would make sphere look uselless and super boy as well.
2nd clue - The frist time he debut on show, his shape and boy look alike Darksied. And how he put Bruno Mannheim and Whisper A'Daire in coma that looks alike psychic coma of Miss Martian. he like torturing even his allies for fun. Sonic weapon could be Apokoliptan´s weapeon.
there is other clues like he is a alien. He was mentioned in episode "Disordered", and in this show everything is connected.