Syndra's powers and weaknesses

I think it's become clear that Syndra's an extremely strong pick. Not only is she a strong control mage, but she also excels at bursting down foes in the blink of an eye. I understand that this was the purpose/vision of Syndra; however, it's becoming confusing for both players going against and picking Syndra what her strengths and weaknesses truly are. Perhaps, one of the biggest things I can point out is Syndra's damage potential even after her death. What do I mean? Well, if some of you are not aware, the "plan z" for Syndra when she is stuck is: "Spam. Stack balls. Ult and drag someone to hell with you." As a Syndra player myself, I must admit that when I have nothing to lose, I just spam, then ult. I mean, gosh, this play style is reflective of that of Karthus. I think it is better for the community that Syndra's ult does not deal damage when she dies. In addition, I believe that Syndra should require more skill or be adjusted, considering the immense buff she received. Her Q and W buff make it almost effortless to play Syndra. These two buffs must not be accounted lightly because a) Q buff means more ult damage (30% AP + x) and control b) W buff means more AoE --> Easier, bigger stun range, and again, more damage since it is more likely for you to land this spell. If there is any adjustments I can think of in mind is this: "When Syndra dies, her body leaves behind raw power on the spot of her death. Enemies can pick up this power to acquire x amount of AP or AD, etc. The soul only lasts 6 seconds while the buff lasts (x amount of time)." Maybe that ^ with another minor nerf would bring an interesting and healthy gameplay because that makes Syndra the "queen" of her team, creating a tighter teamplay for both teams. This way, Syndra may still be the power & control mage of her team while being vulnerable because of her own power. (Which brings the question regarding her lore, is Syndra really in control of her powers?) So, keeping these things in mind, I would like to ask Riot, what is Syndra's weakness? In my opinion, she has become much like Azir where Azir can pull of the Shurima shuffle while controlling the battle field with immense damage at hand. Don't you think? Please comment.