One time was when i just unequipped the shadow mantle to see if i could do it then i beat it started a new chapter 3 file and beat the knight again i went to the school talked to seam and i didnt get the dialogue why? My best guess is that you need the other 2 shadow crystals for him to give a shit so now im gonna have to start back from chapter one beat jevil then chapter two and beat spamton neo and then through chapter three and beat the knight AGAIN then finally go to the school and talk to seam