User blog comment:IamJakuhoRaikoben/Chapter 394: Juvia vs. Keith, Review./@comment-5303512-20140725112319

I love how the next chapter title is "Tartarus Arc Part 5: Ultimate Pain" (Mangastream Translation), this I bet is the hight of this arc's main theme which is "Pain".

Or it will refer to Hardner's (Rave Master) Tehcnique called Ultimate Pain