Shock Nova

Hi, I've been thinking about making a Shock Nova based map farmer for the upcoming league.
I've never played a spell based character before, so I'd like to get some constructive criticism and advice. Thanks!

POB link
https://pastebin.com/zTEn7Vzj

The jewels are obviously placeholders, and I'm not sure about the items either.

Are there any important passive nodes I'm missing?