To add wildcards, place 1 or more wildcards on the table and apply any number of powers from them. Mark the chosen powers with a marker. Each one you add increases the challenge by a small amount—requiring perhaps a few extra explorations, inflicting the loss of a few cards either directly or through expenditure. You may choose wildcards that you particularly enjoy, but consider adding random wildcards for additional challenge.
Decreasing the size of locations while increasing their number, or vice versa, is a great way to customize your play experience. Or, for a fast-paced game that has a similar level of challenge to Normal mode, combine small locations and an hourglass of 12 blessings plus 2 additional blessings per character.