Dynamic Duos for World Domination

Ri Jung Hyuk  and Yoon Se Ri

Jung Hyuk is a military commander from a high ranking family in North Korea, and Se Ri is a CEO of a famous company and a heiress to a large company as well.
They hold themselves high and are unbending.

Gu Dong Mae and Kudo Hina

I could have possibly put the main couple here... but honestly I think these two fit better.
Though Dong Mae spends part of the show's time chasing our main girl, there is no doubting the chemistry that these two had.
Dong Mae, originally from a low class family in Korea, ended up growing up in Japan and became a "butcher of men". Kudo Hina, although Korean, was married off to an abusive husband, freed herself from his grasp, started a hotel, and became one of the most strong female leads I've seen (I love her so much lol).

Together, these two could have no one to fear, be each other's safe spot, and literally just rule over their little area. <3

Jang Sa Jung and Yeo Wol

 Chief of Bandits, and Commander of Pirates, these two make an impeccable coupling. Yeo Wol's whole demeaner commands respect from her crew, and she holds herself upright and with their safety and wellbeing first right. Sa Jung is much more of a goofy character, he literally brings all the comic relief. His rule mostly lies around his crew's respect of his fighting ability, and I feel his past experience leading troops really helps.
We don't see much of them together... but it's clear from their interactions they'd be a combination worthy of being avoided when crossed.

Zhang Ren Feng and Cheng Jing / Xi Yu

Deadly Ex-Assassin trying to turn to a normal life meets a man with his own past secrets. The movie lets us know he has his own amount of martial prowess though to his wife is a lovable fool who doesn't.
Their martial art prowess, and how their relationship plays out to it's full extent, these two snag a spot on this list. Anyone would have a tough time trying to beat them... and that's just when they're fighting alone. Unfortunately the movie never shows them fighting together, but boy oh boy would that be a sight to see <3

Vincenzo Cassano and Hong Cha Young 

Italian mafia consigliere and a lawyer with questionable morals, this duo is extremely chaotic. Although with a similar goal set, the two interact and slowly grow their relationship. Alone they are powerful, together, they have the demeanor of being ready to rule the world and do what they want.

Wen Ke Xing and Zhou Zi Shu

What happens when a leader of a group of mass murders cut off from the world and an ex-leader and creator of an assassination group meet? Life soulmates of massive power that could overtake anyone and everyone... if they actually desired so.