7th Singularity Babylonia: Cutah free quest is the best AP-saving & time-saving location to farm Ghost Lantern. You'll get around 3-4x Ghost Lantern by spending 210AP.
2nd Singularity: Mt. Etna free quest is the first location you unlock to farm Ghost Lantern.
Rashoumon event (Ibaraki Douji event)
Murder at the Kogetsukan
Inheritance of Glory
Saint Quartz Farming Guide
Best Craft Essence: Craft Essence Tier List
Nero Claudius (Caster, Summer 2017)
Student Council of the Lunar Sea
Piece of Year 2030 (A Fragment of 2030)
Victor from the Moon