Coming from a Diamond Syndra main - Fix her E and her R please!
E: Please fix her QE hitbox. It's as bad as the old Nidalee spears, but Syndra actually stuns and can cripple an entire team after she ults and E's. Picking people off is way too easy for the low risk she is in, and stunning targets in front of your face diving you is not really a problem either as they simply need to be anywhere around the ball to be stunned. The travel time on that QE is too low to let it have such a big hitbox
R: Creating balls for more damage is not really necessary as her minimum damage on her ult is crazy already. Just a simple DFG->Ult with one ball can cripple an ADC (taking your 2 level lead as a solo laner in consideration), putting them to <30%, which I wouldn't agree with as it provides little counterplay. Decrease her base damage and increase the damage per ball to make her more interesting than just a QE->DFG->R machine - because that's literally all she needs at the moment to stun and create a 4v5.
And no, I am neither a random Syndra hater nor did I get stomped by her recently. She has been my favorite champion (with Lissandra) way before she was popular in LCS. She just feels too powerful with her stun as it does not put her in any risk, and sometimes I just shake my head at the damage DFG R provides. Just fix her to be more challenging please, right now she could function fine without her W because the rest of her abilities is already strong enough.
I know DFG is a huge problem as well, but you guys said you were reworking it in the future so I am not even going into that.

- Mitsu
, problem solved, because you are aware that you won't one-shot a tanky target with Syndra unless you do a full combo + another Q or W.
As for