Refrain is a limited CE only available in Kara no Kyoukai (The Garden of Sinners) event.
For the duration of "Kara no Kyoukai (The Garden of Sinners) event", this craft essence gains additional effects.
Work in progress...
Rashoumon event (Ibaraki Douji event)
Murder at the Kogetsukan
Inheritance of Glory
Demon (Demonic) Servants & Enemies
Device Transfer Guide
Best Craft Essence: Craft Essence Tier List
How to farm EXP cards & level fast
Sometime in Summer
Kara no Kyoukai (The Garden of sinners) Event (The Garden of Order)