Reveal the specified number of modifiers from the Grid. Then, choose the same number of revealed modifiers, flip them to the unrevealed side, and shuffle them back into the Grid. These can be different modifiers than those just revealed. (Then, activate Enemies for each Skull you have just revealed, but do not reveal additional modifiers). 

Clarifications:

• Shuffling the modifiers back into the Grid is not optional.
• For each Skull you reveal, you must activate Enemies. Other modifier effects are ignored (since they were not revealed for a task).
• If you reveal more modifiers than currently in the Grid, reset the Grid and continue revealing. See details under: Reset the Grid.