In skirmish, evil or good, play on one ring mode and look for gollum. Once you find him, kill him and take the ring to your fortress. When you get it to your fortress you will be able to recruit 1 new hero. If you are the dwarves, elves, or men of Gondor you will be able to buy Galadriel for $10, 000. She does massive damage to infantry. If you are goblins, mordor, or isengard, you will unlock Sauron. He too costs $10,000. He does massive damage to structures and infantry. The only problem is that he is very slow.
If you play, in a skirmish, as Isengard and find
the "one ring" and birng it to your fortress,
you can recruit Lord Sauron for $10,000. Even
though he is slow, he can destroy most buildings
in two hits. Personaly I useualy go and destroy
the oppositon with only Sauron, just for fun. It
is also fun to watch the soldiers go flying
after being hit buy Sauron.