The sworn enemy ability can be useful if the game is 1v1, as it would be nearly impossible to guess otherwise. On the other hand, to use it, you either need to find neutral creatures from the opponent's faction or fight them. In a game with multiple players, it becomes even harder to guess, as you can never be certain who your next opponent will be. But the bonus itself is quite good. Combined with the luck stat, which elves always have, it results in 300% damage.

Demonlight: While the creatures of the Elves may not be the strongest, they are the most initiative-driven. If their attack stat increased, they would destroy everything with their first attack, but instead, their defense stat increases. Only demons can compete with them in this regard, but they only have two fast units.

P.S. I think the post was written at 11:11.