I don't know, I think Ainz has shown himself to be quite evil overall. In the beginning I thought the series would be more of a hero trying to keep the facade of being evil and always finding a way to rationalize a way to not do evil deeds (and not always managing to), but it seems as the series as gone on that the influence of his human side has been dwindling.
So, I don't know what he has entailed this time around, but it certainly wouldn't surprise me at this point if he massacred the lot for whatever purpose he's deeming worthy.