Didn't those mana stones all come from the bombs the mage tried to set off in the square? Cale's just returning the gift.
No, Cale found a stash of high grade mana stones buried at the shores of the Jungle (when they put out the fire) he knew the location because of the book.
Didn't those mana stones all come from the bombs the mage tried to set off in the square? Cale's just returning the gift.