They aim to kill.
Action/adventure is one of the most popular genres across various types of media, and anime and manga are no exceptions. Thrilling action-packed stories that force the characters to act quickly and wittily, show us creative usage of weaponry with the most bizarre camera angles — that's what's trendy.
Out of all the characters that participate in such activities there's a group that stands out: it's assassins. They are trained to be effective at dealing with various adventures, they have skills that let them deal with a huge variety of targets, they have (most of the time) experience and cold-bloodedness that help them stay level-headed even in the direst situations.
So we've got a list of our favorite assassins here.
10. Golgo 13 — Golgo 13
Golgo 13, who often uses alias Duke Togo, has a past shrouded in mystery, but it made him an extremely skilled gun for hire. He uses a customized scoped M16 for the majority of his jobs and doesn't shy away from any task, provided he will be properly compensated. He also often employs other people as his assistant and has a very strong professional ethic. He has angered a lot of people throughout his career, being a very effective, calm, and collected individual, and is very alert about his surroundings.
9 & 8. Killua and Illumi Zoldyck — Hunter x Hunter
Zoldyck is a family of assassins, and these kids were put through the harsh training and abuse that follows it from the youngest age. Illumi, the older brother, prefers to use specially crafted needles that allow him to control and manipulate bodies and minds through the usage of Nen; Killua, the younger brother, escaped the training that his family put him through (though it's implied that the escape is a part of the training) and joined Gon, the protagonist of the series, with his pair of yo-yos. Ironically, the meeting with Gon and Killua's will to help him in his adventures is what makes him train better.
7. Hei — Darker Than Black
In a world where some people gained special powers after some unexplained events, Hei was a feared assassin even when he was a simple human: he got his nickname Black Reaper back then. He's highly skilled in hand-to-hand combat, extremely agile and wick to react to the environment, and after he got the power to manipulate matter that often manifests as discharging electricity, he became even more effective. People who have these special powers are called Contractors and are known to be cold-hearted, logical, and rational, and that makes them great kills for hire, with Hei being one of the most famous of them.
6. Yor Forger — Spy X Family
One of the most famous assassins in the modern anime, Yor Forger is an extremely skilled assassin. She is collected in combat, incredibly polite, and has a pretty strict set of morals. She lives a double life, and sometimes her assassin part influences her more slice-of-life-ish part, as she's frequently inclined to resolve daily troubles with simple and effective murder. Thankfully, she knows that she shouldn't act on these thoughts outside of work. She's superhumanly strong, and it often tampers with her daily tasks as she has troubles controlling her strength. But one of her main assassins skills is cleaning: she keeps the Forger home spotless after her assassinations.
5. Akame — Akame Ga Kill
Akame was trained to be an assassin from her youngest years, she works for the Empire, and this job requires her to push her emotions deep inside, both in her missions and in daily life. She's not alone for long: she joins the assassin group that wants to overthrow the Empire, and her swordsmanship skills are very much welcome in this endeavor.
4. Thorfinn — Vinland Saga
This show is based on a real-life historical figure, Thorfinn Karlsefni, a Viking explorer, He was wrongfully abducted by the mercenary company who at first wanted to kill him, but his stubbornness made him a valuable asset and instead they taught him their craft and he became a strategic assassin. He was responsible for going through the enemy lines and reaching the commanding officers: he's small, boisterous, and fast, so it was easy for him. He honed his skills hoping to get his revenge, bt ended up using them for a completely different purpose.
3. Koro-sensei — Assassination Classroom
Before he became an octopus-like creature, Koro-sensei was a human called The Reaper. He was homeless, nameless, and became an assassin in order to survive, essentially killing more than a 1,000 people. But one day he got himself an apprentice and discovered his softer side, one that helped him understand that he wants to be kind and good. But somehow he ended up responsible for certain devastating events and in a way to atone for his sins he started teaching kids to kill with only purpose: so they could finally kill him.
2. Risotto Nero — JoJo's Bizarre Adventure
Part 5 of Jojo's Bizarre Adventure is a mafia story, and you can;t make a mafia story without assassins: here they are a part of a Hitman Team. All of them are good at their craft, but one person stands out, and it's Risotto Nero. He's stoic, collected, esteemed professional, and his ability, Metallica, allows him to manipulate metal to make it invisible and kill people from the inside. Despite being a ruthless killer, he has a softer side: he cares deeply about his comrades and his family — the reason why he's gotten into the business is to avenge his cousin's death.
1. Rob Lucci — One Piece
He's a remarkable assassin — dedicated, lethal, ready to get the job done with the minimal fuss and stay silent about it. He's been trained by the World Government since he was 8 and shot through the ranks to become Cipher Pol's greatest assassin. He's extremely strong and cruel, capable of destroying huge crowds fast and easy.