User blog comment:IamJakuhoRaikoben/Chapter 414: Drops of Flame, Review./@comment-1839664-20150109165234/@comment-7418318-20150109175601

I doubt they'd all call it as part of the Tartarus arc.

Though I wonder if the Light Novel material is big enough make it and the Omakes into their own arc or if they'll all become part of the village of the sun arc.