Duel (2017)

(Will contain spoilers)
Similar:
-Major Character Death's
-Crime Dramas
-Cops in both
-One character walks the line between being good & bad
-Child Abuse, adoption, selling organs/children

Not Similar:
-Duel involves clones
-While Duel has clones one is good, however the other is bad (but can be seen as good) whereas Kill It's main male lead is the one who is bad (but can be seen as good)
-Female Lead is the cop in Kill It, Male Lead is the cop in Duel
-Duel has a more fantasy/science-fiction feel to it whereas Kill It is more realistic

Both are OCN dramas that are dark, intense and touch upon medical ethics. Both dramas are not suitable to be view by younger children.

Simply because the robot is basically a clone of the main character.
Like in Duel Sung Hoon and Sung Joon are clones.

Both have parents worried about their daughters and frantically trying to save them - both include some strange elements. Both are suspense thrillers.

The ML is the result of human experimentation. Some dark themes and tragic, sacrificial ending of one of the characters. Very similar tone and settings.

Both leads are desperately trying to save their loved ones. Also, both are filled with suspense and mystery.

In both dramas parents are trying to save their daughters. Both are suspense thrillers with lots of action.

ML is the result of human experimentation. Dark themes. While Duel has a more upbeat ending, neither is perfectly happy.

Both male lead act multiple role in the drama, male lead is a detective, solving a serial murder case. Yoon siyoon and yang sejong
are great at portraying each character.

Here the main protagonist and antagonist is played by the same person that is Yang Se Jong. Here the both protagonist and antagonist are twin brothers who were experiment of an organization. The similarities between both the dramas is that both villains suffered a lot from their childhood and at last they died but in duel the villain was not betrayed he tried to escape from bad people instead. Also Kim Jung Eun is present in both the dramas

There is somewhat of a spoiler in this review for both dramas.
The only similarity is the twin aspect. I find the twins in both Arthdal Chronicles and Duel to be similar.

In Duel Sunghoon and Sungjoon are mere clones however, the two are very different. Saya in AC reminds me of Sunghoon so much. The two are both very stylish and the more well-kept compared to their twin-counterparts. Both of them are very eerie and are super smart. Both Sunghoon and Saya are evil but as a fan you'll find it very very hard to hate the both of them. Both twins are lonely and were mistreated as children.

Now we get to Sungjoon, he reminds me of AC's Eunseom (aka Saya's twin) because they both have a sense of doing what's best instead of their twin-counterparts. These two aren't entirely similar as Eunseom at the beginning and sometimes near the end is very naive this is due to how he grew up. Sungjoon too is naive but this is due to his memory not being fully there. Other than this you still find yourself routing for this twin as well.

Both deal with similar themes of identical faces appearing. The plot remains shrouded in mystery and suspense. Duel is more of a detective story, trying to find out the truth behind the unusual events.

In both shows the leads, while trying to save people they love, end up finding something they weren't expecting... Both are suspense thrillers with badass protagonists.

Both about experiments on kids. We have also some revenge aspects and mistery. A lot of actions and suspense. Strongly recommend it.

- both main characters lose their memories and struggle to remember them
- both dramas are dark and focus on uncovering the crimes of powerful people