Unlocking Cards and Obtaining Achievements Explanation
Cards are unlocked when you discover them for the first time during a run. When presented with a “Found Card” or “Choose Card” prompt, if it has the “New” banner on top, it means you haven’t unlocked it yet. Once you select that card as choice, it will unlock.
Achievements unlock new Summoners. Each Summoner has 1-3 achievements required to unlock it. When you unlock a Summoner, you also unlock their starting cards. Additionally, you unlock their All-star deck in battle mode (though, not all the cards in the all-star deck).
Unlocked cards can be picked as starting cards (except for Guardians, they cannot be chosen as starting card). Additionally, any unlocked cards (including Guardians) can now be chosen to build custom decks for Battle mode.