The Marvel Universe is best known for its flawed heroes and malevolent villains, but it's safe to say that their assassins get to have the most fun. Free from debating over right or wrong, they're more concerned with making bank and taking out undesirables. All that contemplation over great powers and great responsibility is so boring, you know? Let's lock and load!

For whatever reason, comic fans are drawn to mercenaries. We can't get enough of them. But why? Perhaps it speaks to our sense of wish-fulfillment--characters who live by their own code, and have little time or concern for social niceties and proper pecking orders are inherently appealing. Who doesn't want to kick ass on their own terms? Assassins are good at killing and getting away with it. And perhaps it's for all those reasons that Marvel is seemingly overflowing with them.

So in honor of these amoral, antagonist anti-heroes, here's our list of the best and baddest of the bunch: from the cool and calculating to the unhinged and savage. If they're feared by heroes and villains alike, you'll find them here.

NOTE: for streamlining purposes, our picks for assassins fit the following criteria: they either kill for money or have been coerced/brainwashed into the trade from government or criminal pressures. (In other words, don't expect to see The Punisher, who is an independent killing machine. We know--we love him too).

Without further ado, let's meet the 15 greatest assassins The House of Ideas has to offer. Just keep a safe distance, okay?

15. Crossbones

Crossbones Cover Art by Will Burton

Crossbones (aka Brock Rumlow) was a former street gang leader before he attended Taskmaster's school for criminals. Soon, his mercenary skills -- including hand to hand combat, mastery in all forms of weaponry, and ingenious tactical skills) were in high demand. Crossbones went to work for Captain America's arch-villain the Red Skull, and assembled the Skeleton Crew to aid him in attacks on Arnim Zola and The Hellfire Club.

Crossbones' killing skills were most notably used in the Civil War tie-in The Death of Captain America, when he manages to assassinate Captain America (with the help of a brainwashed Sharon Carter).

Rumlow is certainly a villain to be feared. Not only is he highly trained in the art of death, he's not above torturing his targets for intel before delivering the fatal blow.

14. Spider-Woman

Spider Woman

Before she became a hero, Jessica Drew/Spider-Woman worked for HYDRA as an assassin. In truth, her recruitment began while she was still in the womb (thanks to a freak accident involving her mother). As a result, she was born with arachnid-derived superpowers, and believing HYDRA was a force for good, she gladly joined their ranks.

Drew was trained in the ways of contract killing by the aforementioned Taskmaster. Her training was so severe that she believed herself to be a mutated spider, and not human at all. This brainwashing made her all the more cold and dispassionate in her work.

Drew would eventually snap out of this mental state and use her powers and kickassery to help fight alongside S.H.I.E.L.D., The Avengers, and on her own as a private investigator and bounty hunter. Her assassin skills remain in check, but still accessible if needed.

13. Daken

The son of Wolverine acquired his assassin skills under the tutelage of The Winter Soldier. Daken is particularly cruel; he often makes his targets personal, be it his father (who he eviscerated just short of killing him) or his love interests (poisoning a girlfriend to death after deliberately seducing a male stranger in front of her. Oh, and then he killed that guy, just for his passport). He's not a very nice person.

Daken has a formidable array of powers: like his dad, he has adamantium claws and a healing factor, but he has some crafty additional skills as well, including the power to manipulate pheromones and to resist telepathy.

Daken is the true bad boy of the Marvel Universe. Fans love him even though they shouldn't (anyone associated with both the Dark Avengers, Dark X-Men, The Brotherhood of Evil Mutants, and the Horsemen of Death mantle is bad news). He's an assassin you hate to love.

12. Domino

Marvel's Domino

One of several mutants to make our list, Domino has the power of "luck," or the ability to generate random telekinetic events that increase her odds of success while putting her targets at a disadvantage. Her expert markswoman and fighting skills increase her chances of putting you six feet under as well.

This makes her a fine fit for the assassin lifestyle, be it as a solo act or working in tandem with groups like The Six-Pack (a particularly ruthless bunch that could care less about shooting innocents caught in their line of fire). She's also taken missions in Iran and fought against HYDRA. She even plays nice now and then, working alongside X-Force, S.H.I.E.L.D., The 198, and the X-Men.

Whether you need someone to track down The Punisher, kill a dictator, or take on Cable and Deadpool, Domino should be saved in your contact list. She may be just the kind of luck you need.

11. Fantomex

Based off the classic Italian comics character Diabolik, Fantomex is one of the quirkier Marvel assassins out there (coming from the mind of Grant Morrison, could he be anything less?). An escapee from the Weapons Plus program, Fantomex was designed to be a flesh and blood Sentinel (aided by nanotechnology), tasked with taking down other mutants.

Fantomex has a host of complex abilities to aid him in his quest, including the ability to read body language, to cast illusions, and having multiple brains (to be deployed if one is damaged in combat) and E.V.A., an external nervous system that, when released from his body, absolves him of any sensation of pain.

In other words, he's a grab-bag of bad news if you're a mutant on the run. Luckily for said mutants, he turned over a new leaf and has started fighting alongside The X-Men and X-Force. He may very well make his big screen debut with the latter team in the near future, in fact.

10. Taskmaster

Taskmaster - Marvel Villain

Taskmaster has one intimidating resume of applicable skills. He's a genius, a master in all forms of combat and strategy, and, most importantly, he has photographic reflexes. This latter skill, the result of a medical experiment, allows him to mimic the fighting style of any opponent he should face, while also granting him the ability to predict the movement of his prey.

The character has faced off against heroes and villains alike, taking any jobs that pay the most handsomely. In addition to racking up quite a formidable body count on his own, he's also tapped into the lucrative market of training other villains (including the aforementioned Crossbones and Spider-Woman).

His teaching skills imbue his pupils with firsthand knowledge on how to take down other superpowered denizens by learning how to use their own abilities against them. That's why he makes the big bucks.

9. Sabertooth

Sabretooth X-Men

One of the most bloodthirsty and savage entries on our list, Sabertooth/Victor Creed is truly an assassin in a league of his own. Creed isn't interested in the particulars of his profession, as long as it satiates his psychotic tendencies. In other words, he likes murdering people. A LOT.

One of several Weapon X beneficiaries that was roped into the murder for hire business, Creed uses his deadly claws, teeth, and regenerative abilities to his advantage. And he's been in the profession for a long time, given his near-immortal lifespan, completing missions in Russia, Vietnam, and Canada (to name but a few).

But it's Sabertooth's loose cannon personality that makes him so dangerous, often abandoning his professional tasks in order to pursue personal grudges, most notably his longstanding feud with The X-Men and Wolverine in particular (more on him in a bit).

8. The Winter Soldier

Bucky Barnes as Winter Woldier assassin in Marvel Comics

The big reveal that Captain America's departed sidekick Bucky Barnes was not only alive, but also an assassin for the Russian Government (or HYDRA, if we're talking the MCU version that's appeared in Captain America: The Winter Soldier and Captain America: Civil War) is one of the great all-time shockers in comics history.

Retrofitted with a cybernetic arm and brainwashed to perform terrorist acts for Department X, Barnes is one of the most deadly and precise assassins in the Marvel Universe.

Barnes would eventually break free from his Russian superiors after Captain America helped him regain his memories. He then returned to being a hero, even assuming Cap's mantle as the Star-Spangled Avenger for a while. But he'll never be totally free from his assassin days, and he isn't afraid to go rogue when he deems it appropriate.

7. Gamora

Gamora Most Deadly Woman

This Guardians of the Galaxy member and adopted daughter of Thanos isn't one to be trifled with. The last of her kind (the Zen-Whoberis), Gamora was trained by her surrogate father to be the ultimate assassin, promising her the chance to avenge her family.

Her training paid off: she's not referred to as "The deadliest woman in the whole galaxy" for nothing. Endowed with super strength and the ability to heal from any injury, she's a straight-up killing machine. If you need further proof that she's a badass, she's famous for slaughtering every member of the Universal Church of the Truth for their role in her people's genocide.

Gamora would go on to denounce her evil adoptive father and fight for good, but don't think that that change of heart came along with a newfound sense of restraint on the battlefield. She's still just about the worst person to cross in outer space, even more so after being cybernetically enhanced by her Dad.

6. Black Widow

Artwork depicting the Black Widow holding two guns in Marvel comcis

The Black Widow (a.k.a., Natasha Romanoff) is best known as a heroic member of Marvel's Avengers, but her early days were of the more morally dubious variety. Trained by the KGB to be a spy and assassin, her world-class physical conditioning and sniper skills made her a deadly opponent.

She was essentially a blank slate, a human created to be a living weapon -- brainwashed, reprogrammed, and endowed with special abilities including an enhanced immune system and a decelerated decrepitude.

Eventually, Romanoff tired of her wicked ways and defected to the U.S., working alongside Earth's Mightiest Heroes, S.H.I.E.L.D., and other allies of the forces of good. While her days as a hired killer are over, she still enjoys kicking ass, using her patented stinger wristbands to maim rather than murder.

5. X-23

X-23-NYX-4

Wolverine's cloned daughter is a chip off the old block, as they say, and a deadly one at that. She's far more dangerous than her waifish appearance would suggest, brandishing adamantium claws on her hands (and feet!) and harboring the same healing factor abilities as her kinda sorta dad.

Robbed of a loving childhood, X-23 (aka Laura) was raised to be a lethal lab rat by the shadowy organization known as The Facility. They trained her well in the assassin arts, where she showed an aptitude for weapons, explosives, and hand to hand combat (naturally). X-23 has tried to leave her days of wanton slaughter behind her, joining the X-Men (and later) X-Force and using her powers for good. Be that as it may, she'll never be entirely free of her blood lust: if she's exposed to a "trigger scent" (a result of her conditioning) she flies into a berserker rage, killing anyone in sight.

And yes, you should definitely be rooting for her to get that solo movie that Logan director James Mangold keeps talking about.

4. Wolverine

Wolverine Healing Factor

Long before he became everyone's favorite gruff but lovable mutant, Wolverine was less of a human than he was a feral beast. Enhanced with an adamantium skeleton by the Weapon X program, Logan was also robbed of his memories, brainwashed to be the ultimate mindless killing entity for the Canadian government.

The problem with turning a man into a feral instrument of death is that things don't end well when he gets fed up with being ordered around. Logan would escape the Weapon X compound by slaughtering every soldier in his path.

Wolverine has tried to leave his murderous past behind him, fighting alongside the X-Men, The Avengers and more, but where his other costumed compatriots shun the idea of killing, Wolverine still uses his deadly skill set to murder when his berserker rage comes a calling (or to deliver the occasional mercy killing). You got a problem with that, bub?

3. Bullseye

Bullseye holds two knives from Marvel Comics

No one knows his real name, but with a name like Bullseye, his reputation speaks for himself. A brutal, unhinged psychopath, Bullseye uses his twisted mindset to carry out murder for hire assignments from the likes of Kingpin or working for the U.S. government.

What makes him so dangerous? It's not just his keen hand-to-hand combat skills or his adamantium-laced skeleton, or his ways with a knife or a gun: any household object is a potentially deadly weapon if it's within his grasp.

Whether acting as a sworn enemy of Daredevil or working under the guise of good with the Dark Avengers, Bullseye is definitely a character to be feared, but also one to be respected, if only for just how good he is at dishing out death.

2. Elektra

Elektra deadly assassin in Marvel Comics

Elektra is one of the most seductive women in Marvel's history, but she's also the deadliest. Growing up in Greece, Elektra Natchios's traumatic childhood led her to learn martial arts and combat skills to protect herself from any further abuse.

She parlayed these grim gifts into a profession as a professional assassin working for The Hand, who trained her to become an expert dealer of death, most specifically utilizing sai swords to slice and dice her prey. Elektra's profession has put her at odds with Matt Murdock, the love of her life. The fact that she was hired by the Kingpin to kill Daredevil (not knowing he was Murdock in disguise) hasn't helped things much.

Elektra would die facing off with the aforementioned Bullseye, but the character (created by Frank Miller) was just too damn cool to stay buried for long, and she has been resurrected multiple times over the years. While she may be able to cheat death, anyone in her sights won't be as lucky.

1. Deadpool

Deadpool speaks to the camera in Deadpool

"The Merc with a Mouth" had to come in at #1 right? Wade Wilson is the best assassin in the Marvel Universe: a master of swordsmanship and gunplay, he can heal from any injury, and he has a literal bag of tricks that gives him additional powers including hologram projection and teleportation.

Despite his qualifications (including a stint in the military and the CIA), Wilson is extremely mentally unbalanced, making him a bit of a wildcard for anyone hiring him for his mercenary skills. His panache for murder also comes with a bizarre moral code, however, one that affects his decisions on who to kill: he must be convinced his targets deserve to die in order to accept a job. The character uses his unpredictable nature to his advantage; you don't always know how Deadpool will accomplish his task, but you can rest assured that his targets won't make it out alive -- even if he has to "die" a few times himself along the way.

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That wraps up our list of best Marvel assassins! Which ones are your favorite? Let us know in the comments, and be sure to check our lists of best DC Comics assassins as well!

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