Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This is how I play the Tiny Master of Evil. He does a lot of damage and has good survivability. You will actually be right around 600 AP if you finish this build (although you normally dont get past Rylais or Zhonya). To give you an idea, with 500 Ap you will take away 45 percent of their health, then have the capacity to easily do 3000 more damage all your spells. Plus you slow anyone you hit with dark matter because of the Rylais. Combine that with your ability to stun and break up a team with event horizon, you are actually a force in the game.
Start out by playing defensive and harassing, use baleful strike every time you can.... it will net you an extra 100 ability power easy. Make sure you last hit with it. It should be the first thing maxed, followed by dark matter. Event Horizon is the last thing you should max and only needs one point to start. Primordial Burst gets a point whenever you can.
Remember, you are not a character that should be in the front line! Even with over 3000 health, you will die! Wait for your team to engage, cast event horizon around as many of the opposing team as you can, then nuke a squishy with everything you have. Alternately you can use Deathfires active to hit a tank and deal 1500-2000 quick damage to them then nuke him and kill him. Dont forget about the active ability!!!! It does too much damage not to use it!
I hope this guide helps. I plan on expanding it soon, but I think it is a good build and is much more effective than the glass cannon builds.