TFP soundwave being a sassy boy is the best HC, but in addition I like to imagine that Soundwave acts stoic and edits his voice to be really menacing. He actually sounds like a 21 year old and acts like one too. This brings me to a scenario (regarding how the humans mistake SW for Arcee because of his legs) that KO for example would point out that he has feminine legs and that leads to ‘You know what these legs can do?’ ‘What?’ Then SW proceeds to gracefully jump and kick KO across the room.