User blog comment:Kiraofthesky/Anime filler/@comment-5303512-20150912081458/@comment-7418318-20150912082052

For #1... I think that they might go on with the story as it is, but instead of summarizing things like in the manga, they might insert a full Zero sub-arc at that point when Mavis explains everything to the rest of Fairy Tail.

It'd be a quite fitting place I think, since nothing much happens in the main story at that point anyway and with Mavis already explaining what happened back then it'd feel quite naturally placed.