Can challenge coins be saved and used for Atlantis Rises?
Only one of the 5 challenge events whose symbols are on the coin.
Guardians of Teltoc
Knights of Avalon
Pirates of Correlia
Riddles of Wonderland
Fables of Grimforest
No, challenge coins can only be used for challenge summons. You can hold them and use them at a later challenge but they cannot be used for Atlantis.