Twitch's damage is great and his range with his R makes him safe in a team fight. Most of the time you used to do this and the enemies would turn to you and one tap you but with PTA you can burst them down so fast they won't know what hit them. The most important item at the moment is probably Lord Dominik's Regards. Tanks are just such a huge issue in the game right now and especially for AD Twitch. The old solution was rushing for Blade of the Ruined King but the armour pen and extra damage make this the better solution at the moment. The main issue with Twitch is his lack of movement during fights. The best solution for this is Galeforce; this trades off the damage or Kraken Slayer and is a better option when playing against less tanks.

During the early game, Twitch's damage is okay which is where the extra damage from PTA comes in to give you some much needed burst damage to win trades against long trade adcs. If you get caught out as Twitch there isn't much you can do as he is squishy so you need to make sure to not misposition and get CCd and make sure you have river warded for anyone trying to gank you as most junglers in the meta right now can just run at you and murder you there and then. You'll want to engage with your support, so, for example, lets say a Nautilus hits a hook, you'll want to on the enemy and start your so you can get the burst of attack speed, Using Ignite early is key so that the don't get out on 1hp or use heal before you ignite. If you ignite before they Heal they will have to wait for your ignite to finish to heal otherwise it will heal for like 10hp since ignite applies Greivous Wounds. Get them low with your autos and PTA extra damage and E once you have max stacks on them and they are out of your AA range as this means that you won't lose the time you could have autod while casting your (your takes time to cast and hit so you need to make sure you don't die before casting it).

Once you've hopefully secured a few kills or have played safe and have a fair amount of cs, you can go on a roam with your support to mid and try and secure a kill there as the invis in Twitch's makes his ganks unexpected. You want to try and move behind them so that they are inbetween you and the laner while your support comes in from the bush to CC them. Securing a kill will not only give you and the people contributing gold, but also keep team morale high and reduce people from tilting and running it down.

By late game with this build you will be melting people faster than they can say hippopotamus wtih your attack speed from your and the high damage from your , just make sure you don't get too close otherwise assasins like Zed or fighters like Fiora will just burst you to one hp. You'll want to always have your for the tankiest on their team as the extra AD from it will demolish everything they own and love.