This craft essence is currently unavailable on the EN ver.Seaside Luxury is can be purchased from Dead Heat Summer Race! event shop.
Here is a list of servants & CEs that can be obtained for the duration of the Summer 2017 event part 1: Dead Heat Summer Race and part 2: Death Jail Summer Escape.
Rashoumon event (Ibaraki Douji event)
Murder at the Kogetsukan
Inheritance of Glory
5 Star Servants Tier List: Best Servants [5/9 updated!]
Best Servants [★4]: 4 Star Tier List
Demon (Demonic) Servants & Enemies
Saint Quartz Farming Guide
Setsubun Event Boss Guide
FGO Reroll Tier List [5/11 updated!]
Best Craft Essence: Craft Essence Tier List
Archer Inferno (Tomoe Gozen)
Piece of Year 2030 (A Fragment of 2030)