Name characters who may as well qualify as anti-villains( link).
Gutoku Asanagi and Airi Yūnami from Qualidea Code.
Airi was an extradimensional alien(Only called an Unknown) masquerading as a human and initially considered the human children tools, but eventually began to consider them family, she even desired to have a child of her own, and had been willing to die for the sake of the children's future.
Gutoku was an actual human who joined her side when they fell in love(He wanted to escape the war with her, but she couldn't do that due to her role as gatekeeper), and had cared about the children as much as she had.
Following Airi's death, she met Gutoku one last time in spirit so she would ask him to live on and take care of Aoi Yaegaki(Who seems to be their child).