After their first meeting, Sugar became very protective over Niffty and often treats her like a helpless child, despite the fact that they aren’t far apart in age.
There's a theory speculating that sinners who sold their souls have back eyes. Husker's has fully black eyes and Angel only has one black eye(because he didn't fully sold his soul. Contract stating thay Val can do anything Inside the studio)
I noticed that only her pupils are black.
I didn’t write her with that theory in mind, but Sugar did sell her soul to Alastor.
It still hasn’t been confirmed whether or not overlords can make deals with humans before they end up in hell, but in my AU, Sugar was able to summon Alastor while she was alive and she sold her soul in exchange for help “escaping” her situation.