I'm not sure what u mean by "Psycho" because not sure if there are dramas with both sides real psychos .
psychological game between cop and killer where some point both are psychos (not so normal and decent):
Lucifer masterpiece revenge which almost drives crazy target cop
Hello Monster great drama, very smart ML vs/and kind of with psycho serial killers
Duel
Gap Dong
A Man's Story SML is almost villain and quite psycho, also it's rare case when bad (but very charismatic) guy kind of wins (every character in drama, including his father and sister, except for FL are against him but he never looses, he is very smart)
Psychopath Diary this one is kind of comedy but maybe only one where both are real psychos (guy who thinks he is serial killer and real serial killer) really good watch