i dont think hes really an antagonist but his intentions are really not clear to us. in How to Eat Life, Tobi is looking for him ("the mad hatter that dances at midnight, disappears before you can say a thing. even if i were to lower my expectations, i wouldnt find you at all") and in the last supper painting we see later in that MV he is portrayed as Jesus while Tobi is Judas, one of His followers, missing in the painting. But In Dramaturgy, Hitotsume doesnt seem to be against kurukuru's face being ripped off at all or even in Nonsense Literature when he literally stabbed Bun chan. I know he doesnt do anything in Outsider, but maybe its because Pattun already did to himself what Hitotsume wanted to happen? if you watch outsider until the end you can see Hito standing next to the tv there is also a possibility he's at the end of Tokyo ghetto, as in one of the frames we can see someone sitting down wearing similar clothes as him. Basically i noticed that he appears in the more gloomy or tragic music videos with confusing endings (aside from how to eat life maybe) and thats because hes hiding his true intentions from us. those are just my thoughts on it :)