An idea for Zoe's W

Talking with some friends I came up with this (feel free to disagree and call me mad, I just wanted to share).

Zoe was sold as a burst mage with some crazy but situational movility. And her W falls to deliver that usually because it depends on spell stealing, and usually it's just a frustrating thing because the addd burst or healing from items.

What if Zoe's W was a flash with her current balls, but it worked with a spellcasting builtup like Kassadin's E. This would give her a situational high movility and would remove randomness.