Once finally coming to the realisation that he had only been trying Julius for his own gain, King felt rather glad to have made that realisation. It was as if a huge load was lifted off his chest as he could finally accept himself for what he was instead of trying to pretend like he was a noble hero. That was probably what had allowed him to realise why he wasn't so good at being a teacher to Julius. That would also explain why he couldn't teach Julius properly himself and requested assistance from Seven. That would also explain the sensation in his heart which told him to be on the ready for a wonderful fight whenever he was around Julius. It was as if his body could sense the feeling that a battle was about to begin every time he was close to Julius.