She's the most powerful for most of the beginning of the story, this is based off the manga not the anime, but as the story progresses there are more enemies that are about her level so its hard to distinguish her powers over the others.
Even the anime series makes her weaknesses so obvious that she wouldn't even be a contender against any of the other characters people are mentioning. Just need to beat of Tsukune before he takes off her cross or douse her with water and finish her off .
Now I really wanna watch YYH to see why certain characters are always mentioned in these threads. ^_^