Diana Buff?

i think diana needs a buff to keep up with all the other champs. because of her nerf to her passive i feel she has trouble against certain match ups that she should normally win no problem. seeing how heimer and leblanc got a good buff i feel diana is deriving of one because i feel she is a good counter pick or just a good pick in general agianst mid champs.
. Why did they have to make her E take your mana to give to an ally? It makes more sense, but she was such an epic support before that, now she's even more mana hungry than before.