As Dante kept talking with Forty-two, he noticed that the android was having a difficult time deciding what to do.
The last command she was given was to protect the necrotic core, but the main command overwriting it was telling her to protect the people of Novaria.
Since there was nobody inside the room besides Dante and Forty-two, the warlock suspected that the necrotic core was affecting the android.
Being exposed to such intense magic for a long time could make a human go mad, especially if they had to listen to the wailing of the dead for days. However, Forty-two wasn't a human, so it wasn't clear how it could've affected her.
The android mentioned that the whispers were from the people she was meant to protect, and Dante pondered if she felt guilty for being unable to save them.
"Do you know what these cores are made out of?" Dante asked the android, curious to know her perspective.