User blog comment:Omega natsu2/Chapter 364: Tartarus Arc, Part 1: Immorality and Sinners, Predictions./@comment-112.198.90.65-20131217062144/@comment-7418318-20131217140703

On that I think we all agree. Especially now that there are three kinds of curses. Once the "normal" curses on items or people, curse magic (those two might actually be the same... or not...) and the demonic curses Tartarus uses... and none of the three were really explained.