Fantastic Beasts: Ranking Every Character From Worst To Best

For what we see of Mary Lou Barebone, she's an effective character: she's the typical militant pious figure, quick to violent punishment, all too hard on children and generally a bit of a one-dimensional sub-villain cliche.

She's enjoyable enough to watch, but it would have been perhaps better to discover she had links to the the historical Scourers that JK Rowling introduced in the run up to release. That would have given her more complexity, though it perhaps wasn't needed.

In another world, Barebone would have been the villain of a straight origin story for Credence Barebone but this isn't really his story, and it's certainly not hers, so it's simple enough to forgive the lack of depth.