That champion is completely and utterly overpowered, for the simple reason she's got overwhelmingly high damage, crazy low cooldowns, and exceedingly high range.

She's also got great utility on both e and w. In addition to both spells doing tons of damage. Finally her ulti assassinates enemies better and safer than a lot of assassins and fighters.

Her payoff is way too much for being "a squishy mage". And she's not even hard to play. She completely outclasses champions like Orianna and ahri.

Imo her numbers need nerfing imo. High base damage on her abilities plus great scaling plus the max rank increases.. Goodness gracious.