This craft essence is currently unavailable on the EN ver.Dive to Blue is can be purchased from Death Jail Summer Escape event shop.
For the duration of "Death Jail Summer Escape" event, this craft essence gains the following effects:
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.
5 Star Servants Tier List
Best Craft Essence
Oda Nobunaga (Archer)
Best Servants [★4]
Zhuge Liang (Lord El-Melloi II, Waver)
Cu Chulainn (Lancer)
Piece of Year 2030 (A Fragment of 2030)
Talk on the Heated Sands
Victor from the Moon