Author is a woman, by the way.
I'm guessing by the 106th chapter or so she began to realize there isn't really that much more she could do to extend the story to explore the already strenuous connection between the ouendan club hijinks and the time travel, so she decided to outline an ending and start it with a pre-redemption downfall arc (you know like in movies where the hero has gotten used to his powers only to meet a massive obstacle or letdown, which the hero eventually manages to overcome right before the story's ending). I realized this after reading the Japanese raws up until the end and re-reading the scanlations. This is the beginning of the end, so enjoy it while it lasts.