T.O.G. Entertainment.com announce an review of their expansion for Underworld:
From their announcement:
The first Expansion Set for Elemental Clash, Elemental Clash: Underworld Expansion The “Fat Pack”: This pack contains all the cards of the Underworld Expansion Set. So you get a total of 216 cards, which you can use to customize the original Basic Set further or build several new decks altogether.