Board Thread:General Discussion/@comment-4636650-20161205141818/@comment-25926288-20170123170842

Hmcooper4 wrote: Agreed. And also avoid the born psychopath, which they used with Cruella. That was fresh with her (and likable in it's own way), but that really is a one-time use.

Honestly, a good reason for the black heart might be conflict between her and Blue, and that conflict drove her to abandon the Fairy morals. Blue did say her heart turned dark, so I think she has an innocent start. Sadly we never did see Cruella's heart but I assume Psychopath/Sociopathic tendencies might arise from a pure dark heart. I think Cruella is probably the only one we know with a pure dark heart (besides Nimue probably).