i might deny this if its even brought up again since i love her and dont want her touched any more :P
utility.....
imo its why riot keeps her where she is, as squishy as she is, as slow as she is, and continues to nerf her... she is amazing.... they might take her completely out of rotation one day if they cant nerf her enough =^D
her healz are sub par... ok?...but she healz...thats lane sustain... and multiple people at a time, at a great distance...and not for complete crap ya know compared to a support that doesnt... and she also has a full team shield....
and did you know her movement buff give full team... let me say that again... full team movement buff about 15%-30% (early - late) easy with no investment ...
you want a hec/yi/jinx/rotating grp sona is always ur girl
and add to that her signature poke... and a poke to be feared by adc's who thought they could build just damage, or supports who thought armor was enough..... she is the yin to the adc's yang
but again... and i hate to admit it... im a bit of a "fanboi" about her, so maybe a grain of salt is needed with my opinions.....