Camelot : Wastelands of Death (Free Quest) is the best AP-saving & time-saving location to farm Chain of the Fool. You'll get around 6x Chain of the Fool by spending 190 AP.
Rashoumon event (Ibaraki Douji event)
Murder at the Kogetsukan
Inheritance of Glory
The Azure Black Keys
Oda Nobunaga (Archer)
Black Tallow
5th Singularity: E Pluribus Unum
Servant Rank Up Quests (NA)
Ereshkigal
Arthur Pendragon(Prototype)
Gorgon
Black Holy Grail (The Black Grail)