While this build just focuses on getting AP and some magic penetration, this doesn't really give you much sustain so I highly suggest you use Consume as much as possible to stay in lane longer.

While in early game, harass the enemy with your E and use Consume to stay in lane. Around mid game the enemy (if they're smart enough) will have some magic resist mixed in with their builds. If you're having trouble against your enemy, get a Void Staff first instead of Rabadon's Deathcap for some more magic penteration and Rylai's Crystal Scepter.

You sorta need to get fed for this build but with the insane damage you deal at early game, it shouldn't be a problem.

Have fun ;D

For summoner spells, I recommend Clarity with Exhaust or Ignite