Yep I get it. The glasses are making her insane. It even says in plain sight in Lilith's profile that her time under Octavio's control drove her insane, which is why she is what she is right now. Those glasses are a mix of a cigarette and drugs. Drugs can make you crazy, and cirgarettes can make you have withdrawl symptoms if you go off of it for a while. That is basically what Lilith is experiencing. She just needs someone to hold her back from using the glasses, then, she'll return to normal and redeem herself. If she was heartless even without wearing the glasses for an extended period of time, then why didn't she attempt to kill Labrys without hesitation? She didn't. She put the sunglasses first, then "killed" her.