Picking the right AD Carry (ADC) in LoL can be a hassle as there are a plethora of options available. Although it boils down to personal preference and playstyle, some are simply easier to play when compared to the rest. ADCs that are difficult to execute typically have a steep learning curve and are not worth the investment. That said, these champions can also be incredibly rewarding if played efficiently.
Twitch

Twitch is an ADC champion in LoL that, if played correctly, can run away with the game. Since Twitch is a hyper carry, he boasts one of the highest damage in the game and can decimate opponents in a quick burst. However, he lacks mobility and is very easy to lockdown. Twitch is also very squishy and has next to no resistance. This, combined with a lackluster early game, makes the champion extremely difficult to execute.
Samira

Since her release, Samira has been a fan favorite. She has been one of the most played ADCs in the current season, mainly due to her aggressive kit and dominating playstyle. Samira thrives in team fights and can be a menace to deal with. Her all-in potential is off the charts, but she needs teammates to set her up.
Although Samira packs a lot of damage, Samira hardly brings any utility to the table. Furthermore, because she cannot engage independently and relies on teammates if her team performs poorly, she also performs poorly.
Aphelios

While Aphelios is a powerful and flexible ADC champion, maximizing his abilities can be difficult. His passive is convoluted, making him difficult to use. Furthermore, even players who are familiar with his passive struggle to make effective use of it.
Aphelios is also a relatively immobile champion, meaning that he is very prone to crowd control. As a result, if he happens to get locked down by an opponent in a team fight, then he will most likely die.
Kalista

Kalista is a bit of an interesting ADC champion to try and pick up in LoL because she has a very quirky playstyle. One of her most significant weaknesses happens to lie in her biggest strength, which is her passive. Because of her passive, Kalista is very mobile and can easily out-maneuver her opponents and dodge abilities. However, she incurs a significant reduction in damage as a trade-off for high mobility. As a result, getting through the early parts of the game with her and surviving until the late game might be challenging.
Varus

Varus is an ADC in LoL that can be difficult for some players to pick up because he is so skill-shot-reliant. Most of his kit requires precise handling, and without that, his impact is meager.
Varus is heavily reliant on his ultimate. Although it is a good offensive tool, his ultimate is also his only defensive ability. Varus’ ultimate can be used for locking down enemies that are looking to engage him. Without his ultimate ability, he lacks the defensive ability and is susceptible to ganks.