Before the war ignited, Lily was considerably more callow and naive than she is now and would blanch at the mere thought of dabbling with the Dark Arts, abhorring EVERYTHING that sort of magic stood for. But after she graduated from Hogwarts and joined the Order of the Phoenix, her resolve started to slip away, and it wasn’t long before she found herself resulting to curses such as Sectumsempra, Fiendfyre, and Avada Kedavra to fight Death Eaters on the battlefield. Fight fire with fire, kill or be killed, whatever mantra she needed to repeat in order to live with herself. She found that, with her Dragon Heartstring wand, it was easier to cast dark spells than it should have been, honestly, and while she felt no satisfaction or enjoyment from using such terrible magic, she would be lying if she said she felt sorry for the Death Eaters she maimed. She fully believes that they deserved their fate for joining a fascist organization and that ultimately, by killing them, she saved more lives than she took away. She still thinks that there are LINES that must remain uncrossed though. She has never tortured a human being, not even for information. Lily has also never drawn out someone’s death, preferring a clean and quick kill. She simply has no desire to watch anyone suffer, no matter how many horrible things they have done. She doesn’t have the stomach for it, and honestly she doesn’t ever want to reach a point where she’s so desensitized that she no longer c a r e s . She wants to keep some humanity, even if she doesn’t necessarily consider herself to be a GOOD person at this point. Nowadays, seeing as there isn’t really much a war to fight anymore, she only casts dark curses on inferi. And unless the zombie was originally a loved one, she doesn’t struggle with it too much. Their gaunt, cadaverous forms certainly help her separate them from the living, reminding her that walking corpses cannot actually experience pain and suffering. It’s only when the glamour is still intact that she might hesitate, but ultimately, she will do what it takes to survive.