Board Thread:Questions and Answers/@comment-73.19.129.12-20150921004412/@comment-6697950-20150926073832

First off, make up your mind. Are you asking why is she strong, or why isn't she strong?

If you're asking why isn't she stronger, then I have to ask "You want her to be stronger than the main characters? Because that's the only way she could be even stronger than she is now." Leafa is considered one of (if not the) strongest players of the Sylph race, especially in aerial fights. And, according to Asuna, Leafa is her greatest rival in combat.