[3C] [Bug][Suggestion] Reveal Spell doesn't work properly

Reveal cannot be cast upon an area you already explored.  This is inconvenient as I sometimes want to check an area for enemy units hidden by fog before moving back into an area.

I would also like to see another version of Reveal that is less costly and only allows you to view Terrain; does not show troops, cities, etc.  This would help reduce wasting time exploring areas that are impassable or dead ends.