Sworn enemy.

Here's a point about the usefulness of the "Nemesis" ability. Over the weekend, I played a game on the Heroes of Might and Magic III (HoMM3) map "Dragon Pass," with Winged as my hero against Tilseck. I only won thanks to frequently using this ability. We met roughly in the center of the map towards the end of the fourth week. Both heroes were around level 20-21. I developed skills somewhat evenly. I couldn't manage to capture my home territory, although I really wanted to, but I fully developed the "Light" skill tree, including "Righteous Fury" (which gave me both Haste and Smite), and I also took "Storm Wind" (not for the enemy, but to deal with dragons). I spent a few levels on leadership and luck, but I didn't get either "Elven Luck" or the "Aura of Swiftness." However, I did get boots that increased speed and the "Dragon Utopia" artifact with rings that boosted initiative. The result was a classic Winged build with decent artifacts. By the final battle, I had managed to add War Mongers and Goblins to my list of "Nemesis" creatures. I didn't find any others, but that was enough. The battle was very tense. I don't know how, but he had twice as many War Mongers as I had archers, and he had 550 Goblins, while I only had about 150 Dryads. But in the end, "Nemesis" and the "Dervish" skill (referred to as "dancers with the wind") decided the outcome.