That is the thing though, Vulvamort is the worst maybe but remember the talk, she thought she was right, she did the right thing. She probably had terrible childhood because of the family. Steph also the same, she stuck between the duty because of her father and MC because of her love. So that is my point, even if what they did varies they all thought they were doing the right thing expense of their respective MCs.
So being remorseful, having reasons for doing it etc. none of them matters, the damage is done. No redemption for any of them.