The moment she killed her Daddy, there’s no way for her to redeem. She keeps trying to get revenge on Snow, even though it was her mother’s fault and she knew it in the begining. She killed Snow’s dad aka her husband, sent a huntsman to get Snow’s heart, create the curse to seperate her and her daughter, as it wasn’t enough, in the next world, she continues to frame MM for murder. Killed Graham, lured Hansen and Gretal, two kids to the blind witch’s house just to get ..(i forgot get what but it was used for killing for sure). She was cursed by Rum, Charmings helped her, then she decided to kill him as well. If Henry didnt bust in on time, David would be playing cards with Hades. Rumple is evil but atleast he doesn’t kill his father/mother/children.