Without upgraded cards, you can't build a deck to beat all of the false gods. If you have the oracle prediction, you can usually build an unupgraded deck capable of beating the known FG with a good win percentage. For instance, liquid antimatter will pwn akebono, monoair with wings will pwn serket, and so on. There's a few that will be difficult even knowing they are coming, but for most, there's decks in the FG subforum that usually have some effective decks, both upped and unupped.