my pet theory is that the farther and the time mage used the time-reversal magic with each other but the farther chose not to restore his own memories but the MC memories instead. Personally, I think it was done out of cowardice as he does not want to remember that he killed his own daughter but...
@MrEd you may call it filler but I much rather have the same story told from a different perspective than having the same story told with the same perspective with pictures
it's a migraine, this is not a spoiler I don't know what she has but, it's a migraine.
as someone that gets migraines the symptoms do somewhat match and things like bad sleep and overwork can start one