I'm vegajuice (or VegaJ) and im a main/otp Twitch since 5 years (bring back fervor please). My main account is VJKL and my secound account is VegaTheRat. i really love twitch as adc and i know this build is built different.

The build is an hybrid stuff mixing AP AD and ON-HIT Dmg. It destroys frontlines and squishies and with the Mythic passive it improves your AP dmg of and gives you lot of AS and ON-HIT Dps

After your first back, rush one ad item of the like or and then do some AS with

The is a must have and a big spike in damage. After that item you can go with that will give you lot of AS and AP. I think that you can't rush that item on twitch and is better in early because you need dmg as soon as possible.

When you start building you need to rush some the

With four items : & & & your damage are really high on-hit.

If there are no tanks you can go or . But if ennemis start stacking armor (which is higly possible in the new meta) is higly recommend.
An other situationnal item is Nathor's tooth, it can be build if you are scared of ennemy comp and you want to do more dmg on your E than on your autos

Twitch is a really unique champion compared to others ADC. The gameplay is different and hard to explain. When you are beginner with twitch do not try to open team fights because you really need to take in consideration every menace. One CC and twitch can explose easily, so be careful when doing that. With this stuff if you have a great frontline or peel you can easily open fights and destroy frontlines with the many penetration items and the passive