if 2 superman enemies are adjacent, the higher point value fig gets outwit. What if I use my outwit, but then I move one figure so that they are no longer adjacent? Does the outwit nullify, bringing back the outwitted power, or does the power remain outwitted?

The outwit disappears. This is especially important to realize when you use a wildcard to gain the outwit - should they ise another TA, the outwit will also disappear!

Note: The Outwit granted by SE does not disappear until after the completion of the action that caused the SE figs to become non-adjacent.