User blog comment:IamJakuhoRaikoben/Chapter 364: Tartarus Arc, Part 1: Sins and Sinners, Review./@comment-7397924-20131220140411/@comment-4829046-20131220141342

Even though they call themselves that, I prefer referring to them as "People who have sinned" =P Tartaros on the other hand are full-on sinners.