Essence

Essences (極意, Sozai) are special, scroll-resembling Materials that cannot be obtained from battle with enemy Hero Units, but by building the Support levels between any two Hero Units to A/A+.

By combining a Hero Unit's Essence with a Gold Material of that Hero, the player can create that Hero's Skill Boost Crest, but only after the Hero Unit creates their Skill Crest on their end to allow other Units to create it for themselves.

Trivia

 * Due to their nature of Materials that are obtained by raising Support Levels, Essences are the only Material that don't count to being collected in the Convoy after a battle, so the only chance one can see what an Essence looks like is via Crest Market.
 * As Essences are limited to only Support building, they are barred from being used as sacrifices in the Temple for Blessings.