Immortal Cores are a new currencey added in V2.71A used to buy Immortal Core Packs from the Shop.

Immortal Core

100 Immortal Cores are required to buy 1 Immortal Core Pack, which contain 1 Immortal/non-exp Card

Immortal Cores can be gained by buying item packs with Credits or Immortalis. The packs have 1-300 Immortal Cores each. Following the same rarity system as other cards.

Common Core - 1

Rare Core - 3

Epic Core - 5

Legendary Core - 30

Immortal Core - 300