Well, it is exactly what the title says. "Assassin Twitch". I would prefer you use the "Generic" build if you're looking for a ranked Twitch guide. This is for fun and stomping, normals only. It looks crazy, but it works, as long as the enemy doesn't have heavy CC...

Its quite simple. Use your Q(Stealth) and sneak up to a squishy target, such as the enemy marksman, or mid-lane. Pop your ultimate and Sword of the divine at the same time, then start shooting! You do the same thing in teamfights, just sit back in a safe spot. You'll be two shotting carries, and 4-8 shotting tanks, depending on how much armor they have.

Twitch's "CONTAMINATE" is his absolute bread&butter. Most of the kills you get early-mid game will be from a max-range contaminate. Its obvious why you should ALWAYS max this first. Twitch's Q, "AMBUSH", is also a major part of his kit. You can use it to initiate, escape, and even siege. Assassin Twitch probably wouldn't work without it. Twitch's W, "VENOM CASK", is useful for poking enemy laners with the 2 stacks, slowing fleeing champions, or to assist with kiting. It is VERY useful, but not quite worth getting leveled early.

In lane, like all champions, Twitch NEEDS farm. If you cant get on the enemy because of a nasty Braum or Alistar, focus on farming until you can get an opening, or a gank. When you want to start a fight, back-up and use AMBUSH, then move towards the enemies, when you're a short distance away, engage with VENOM CASK and if you have it, RAT-TA-TAT-TAT.

I'v found Twitch works best with offensive supports, Blitzcrank, Thresh, Leona, even Annie.