Within this summoner rift, a battle of patience was being tested. Champions at each other’s throats, yet one is waiting; determining the best timing to strike. Twitch decided that he would prioritize damage above all else, settling to feed off the weaker early in the battle so he can destroy them later. He had watched Morgana in previous rifts tear through her enemies using the same strategy; prioritizing dark harvest. Twitch had one problem: he could not use his venom cask to feed his Dark Harvest. Thus, Twitch realized contaminate would be his saving grace. With this, he knew that when he decides to ambush, sudden impact would increase his damage burst. Twitch chose to test his partial strength and began to realize he needs more. He could not push as much due to his lack of attack speed and is really dependent on his support. Twitch decided to add more to his domination and pursued eyeball collections and relentless hunter to help him scale his damage and chase down those who could stave his hunger. Having finished his Domination system, he chose to take two spells with him; exhaust and flash. These intend to help gather his dark harvest and minimize chances of escape or even to escape his own death.

After determining his first set of runes, Twitch deduced a strain test was needed. He quickly traveled to bot where his test dummy awaited. He gathered some cs from the minions around him and leveled himself to level 6. He then tested what he was missing: he began to realize; he needed more attack speed to be able to burst his damage more. He accurately derived a precision set; using Legend: Alacrity and Cut down. With these, he understood that his attack speed would also scale and he would increase the chances of resetting his Harvest. Twitch set off to decide his bonus. Knowing he is still lacking in attack speed, he decided that would be first, followed by adaptive force to increase his damage, and finally settling on armor for his last, so he could survive longer. The armor was only a temporary decision because it was dependent on the champion he is facing.

These runes allowed Twitch to use his ability to scale using ability power or attack damage, so he had to decide which he would want to use.

This build utilizes twitch ability to go adc or apc. It prioritizes dmg over all and scales late game as do all twitch builds. The items are for apc but the build is universal and can be used to build adc if need be.

These items increase the potential of Twitch's passive and W along with his attack speed. Liandry's anguish also builds on top of Twitch's poison. If wishing to go ad, build the typical true dmg items.

These runes utilize dmg scaling and attack/movement speed passives.
Dark Harvestt
Dark Harvest is used to scale twitch ap and ad base ratios. This dark harvest collections infinitely scales.
Sudden Impact
Sudden Impact increases dmg after using W, this helps to increase the chances of acquiring a Dark Harvest.
Eye ball collection
Eye ball collection helps to scale Ap and Ad dmg. This is another small dmg scale to help boost dark harvest.
Relentless Hunter
Relentless hunter is to boost movement speed which allows you to catch up on Dark harvest potential champs.
Legend: Alacrity
Alacrity is an attack speed rune that will boost help to increase your chances of Dark Harvest potential. Ganking early game will improve this stat.
Coup de Grace
Coup de Grace increases the chance of getting a takedown due to its increase in dmg as the opposing champs health is lower.
Attack Speed
Attack speed is a big need for Twitch to get dark harvest
Adaptive force
Adaptive force increase the bonus of ap or ad the champ is building
armor
Armor is swappable depending on which champ your facing, this will help to keep you alive longer when diving dark harvest available champs.

As this build is a scaling build, it is weak early game. Watch the map and try to gank mid as many times as possible when dark harvest is available. When in lane, poke until dark harvest can be grabbed, if your support isn't able to help. If able to push with support, target the healing support or adc if there is no healer. When in late game play back and clean the team. Each takedown resets Dark Harvest, so when possible to get double dark harvest- go all in.