Syndra should be an AP stacker like Veigar.
For a champion that's foretold to have so much unlimited power, she seems to be.. limited to the amount of power she can obtain in a game.
Her passive feels rather lackluster as well, it's supposed to add "power" to your skills, but you just don't feel the power.
Her passive should contain those Ability upgrades but be renamed to "Untapped Power"
Maybe give her bonus permanent AP after each kill she gets, like 5 kills gives her a bonus 20-30% Ability Power, then at 10 kills she gains "untapped power" and will gain a certain amount of AP after each kill on a champion only.
And her original passive remains pretty much the same, at max level her abilities gain added damage/effects
This way she gets this feel of having unlimited power, otherwise she's just Gohan, wasting all that potential.
?
No really, if she owuld gain such a thing then she would receive HEAVY nerfs in nearly every other aspect.
The stun would be needed to be at least delayed and the ult would than be single targeted. (because everything else would be plain unfair)
She DEFINITLY needs a buff, i mean her winrate is miserable (even through better than Veigar anda few others).