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 my Twitch Guide!
Twitch is a crazy good champion, but most people don't know how to use him. Most people assume that critical is all twitch needs, but no! Twitch, against smart opponents can be very vulnerable. If you follow this guide, you will be able to have Twitch's beast damage but still have OP survival items.
First, i would always buy boots along with 2 Health Pots and 1 Mana Pot. First run, you should have enough money to buy a B.F. Sword. Twitch is pretty useless without damage and should get main damage ASAP. However, if you are forced to go back (due to low health, mana, etc.) you should get the Cloak Of Agility. After earning enough money, i would get a pickaxe to earn a lil more damage.
Now that you have a decent amount of damage, get your Boots of Mobility. This item is very useful with twitch, seeing that once twitch goes stealth he'll be able to have enough speed to go to his designated areas and ready for faster ganks.
Usually, next i would start builiding my phantom dancer with first a Zeal. After earning more money, you will be able to afford your Phantom Dancer. Twitch can't kill as fast with only attack damage, but needs speed and critical as well.
Time to finish your Infinity edge. Earn enough money to buy it and BOOM, a majority of your damage would be hitting 500-600 damage. Oh but it doesn't end just yet...
Now, you still have thre item slots left. I reccommend buying the Sunfire Cape first. Twitch can die very easily, so he needs the armor and hp. Also, sunfire cape adds 40 damage to enemies around you. If you happen to be stealthed, then the enemies will keep on getting damaged and can't do anything about it. In fact, sometimes the champions don't even notice they're getting damaged. And at 1/2 hp or so, you can pop up, use your ultimate, and theyll be dead in 2 seconds.
Now that you have a high crit, high defense, and fairly high hp, time to get even more damage, as well as lifesteal. Build your way up to buy The Bloodthurster. You will now be hitting 280's with non crits, and around 700-800 crits!.
If neither of your teams have been defeated yet, its time to build your Youmuu's Ghostblade. True it doesn't add too much attack, but it also adds armor penetration in case of heavy tanks, not to mention that its will also give your a 83% total crit rate. It also reduces cooldowns by 15%. Some skills, like ezpunge, would be so more useful with low cooldowns. Also, if you active your ghostblade along with ambush and pray and spray, you'll have max attackspeed, dealing 700+ /w expunge being used! I can guarantee that we these items, you'll be able to kill almost anyone within seconds.
Why did I choose Flash and Cleanse? Simple.
Flash-Since you are Stealth, to run away you must have 2 seconds to run away from an enemy. At times, your stuck due to enemy CC. You just gotta flash away! By flashing away, you'll be out of range from your enemy attacks and be able to stealth away safely.
Cleanse-Most people wouldn't bring cleanse, but it is actually a very good skill. With cleanse and flash, you can practically get out of any situation, as well as catching up to enemies with low health trying to use CC on you.
Other good Spells
Ghost is a very good skill for twitch, If you were to replace one of the spells, replace it with cleanse. With both flash and ghost, you will be able to both get out from ganks as well as catching up to enemies quickly. (Probably faster than cleanse in some opinions.)
Ignite. It wouldn't hurt to add a little more damage. Twitch can sometimes be able to be avoided easily. With both ignite, along with your poison, the enemies health will be draining fast.
Exhaust can be an awesome skill with Twitch too. Twitch can be very squishy at times, but with Exhaust, this will greatly reduce the damage of hard hitting DPS champs. Also, they will be slowed, which combined with YOUR slow will make it even better, making it difficult for most champs to get away.