Even though "Lost" featured an evil smoke monster, which terrorized the castaways, executive producer Jack Bender says the show was really more about the monsters within the characters.
VOA: standard.2010.05.25
In the end, it doesn't really matter whether the mirror was evil or if their stories were even mildly believable.
"Grimm" centers around Detective Nick Burkhardt (played by David Giuntoli), who in the first episode finds out he's a long lost descendent of the Grimms and is starting to see people for who they really are -- in short, evil.