Folded
It wasn't real and he knew that but the emotions those screams brought up were not manufactured. It was the personal experience of one of many souls that had been 'sewn' into his own and he was just recalling them again.
'Stop it!' he hissed at the apparition, 'Just because I'm running low on soul power doesn't mean you can run amock!'
That said, he truly did lack the soul power needed to control such memories and emotions from coming to the surface. Usually he would be able to keep them buried deep inside his subconsciousness but now that the 'jailer' was not as powerful, any real-life event might jog something he normally would not want to see.
But it had no effect since the apparition continued to wail despite his warning, developing more and more wounds on its ethereal form forcing him to be a witness to a horrendous crime from ages past.