Ok so Katarina is one of my favorite champions in the game, I love almost everything about her.... exception to her w. I rarely use it I feel like you guys just put it there just to fill an ability spot. That being said it is only a little useful at times by buffing our other abilities, but really doesn't do to much. My thoughts is maybe you change this one ability and give her something that would be a bit more useful to someone playing her, for instance something that slows the enemy down or speeds her up in attack or movement speed. Something that would help in a team battle just something other than what it is currently. So yeah that's my proposal hope ya take note of it, and include it in the following patches. THANKS!
That being said don't Nerf her she is balanced.