Why is it that the expansion cards I bought do not contain all the characters? Does it mean I have to buy more expansion packs?
You are referring to the Demi-God cards? They appear randomly in a pack, sometimes containing 1 and sometimes none. The less economical way is to buy another pack and hope for best, and end up with a lot of extra cards. The better way is to buy the Demi-God cards individually. Check my blogshop for details.