Not many metahumans and superheroes in both DC and Marvel are willing to kill. The reason is simple: kids read comic books too and making your costumed characters amoral enough to disregard life is just barring yourself from a ripe market. That's why Marvel's The Punisher (Frank Castle) is a refreshing superhero made by adults for adults-- he doesn't fool around with half-measures, that's for sure.
Meanwhile, in the DC universe, not many heroes could act as a counterpart for Marvel's resident manslaughterer. However, Deathstroke (Slade Wilson) comes pretty close in both behavior and philosophies. While the superhuman enhancements make him a tier above Castle (he's out of his league, surely), there are other ways the Punisher can still win. So, we're here to explore who's the better killer between the two.
11 POWERS: DEATHSTROKE
Here's the most obvious reason why Frank Castle is no match for Deathstroke mano a mano; the DC villain is simply jacked up with superhuman traits like strength, speed, reflexes, stamina, endurance, and regeneration on top of being a genius that could match Batman tactically. All those make him one of the best supersoldiers in DC. Now, in Marvel, Deathstroke easily rivals Spider-Man in terms of superpowers.
There's just no way Castle could take on that without killing himself in the process and even then, Deathstroke might still survive. Really, in a one-on-one fight with no help from their friends, Deathstroke wins but not without breaking a sweat.
10 FEATS: DEATHSTROKE
Oh, what's that? We need to take preparation into account for The Punisher to win? Well, too bad; giving Frank Castle enough preparation to be able to win against Deathstroke also gives Slade Wilson enough preparation time to win against nearly all of the Justice League... by himself with no proxy battle or nukes.
So while Frank Castle managed to take down all the good guys in the "Marvel Universe" because of a couple of alternate reality stories but it was so implausible, it was never accepted into the canon, unlike what Deathstroke did (even though DC's canon kept changing).
9 PROFESSIONALISM: DEATHSTROKE
When it comes to being the better man at their respective jobs, it's a tough call. The Punisher, depending on his enemies, usually dives headfirst into the fray, leaving a trail of mangled and bullet-ridden human bodies behind. It's usually messy and loud (as is the case against his fights with organized crime), but it gets the job done somehow.
Deathstroke, on the other hand, is classier and more surgical in his approach. He often takes out his targets with calculated finesse and mastery. One thing that does make him a better professional is his tendency to keep improving himself to the point of being a perfectionist. Castle simply doesn't have that kind of commitment nor does he seem to enjoy his job... most of the time.
8 ENEMIES: DEATHSTROKE
Deathstroke being the more powerful individual immediately puts his level on that of the most formidable metahumans in DC. He doesn't have the best strength, speed, or endurance but his fighting skills and guile are enough to turn the tide. As such, Deathstroke (and as mentioned earlier) has made enemies out of the whole Justice League and even other superhero factions like the Teen Titans.
They treat him as a serious threat and certainly do not underestimate him. Meanwhile, Castle's enemies just pale in comparison to the full might of the DC superheroes. His regular main course of gang members and mafia bosses is just a cakewalk for the likes of Slade Wilson.
7 LEGACY: THE PUNISHER
Surprisingly enough, even though Slade Wilson is the more powerful character, he first appeared as an enemy of the Teen Titans (basically Justice League junior) back in 1980. While his popularity is also ramping enough for a soon-to-be-revealed film, Deathstroke's star power is no match for The Punisher's.
Frank Castle is simply so controversial, that he's often treated as the flagbearer of unconventional antiheroes who always resort to murder. Not to mention his first appearance in comic books predates that of Deathstroke's, specifically in 1974 in a Spider-Man comic book. To top that off, The Punisher is a lot more iconic and has spawned many movies, a TV show, and fewer copycats, making him a more intricate character.
6 ORIGIN: THE PUNISHER
As for who has a better origin story, we have to give this one to Frank Castle. His origin as a crimefighter is a story of revenge, trauma, heartbreak, and rage. The result? The Punisher became a sad one-man army who always manages to scrape by the skin of his teeth with every encounter.
By comparison, Deathstroke is more one-dimensional. A mercenary who underwent some supersoldier juju science but became evil instead. It's a tale too common in comic book origin stories and Deathstroke could have been one poor explanation or dialogue away from being generic that his deranged Marvel copycat became more popular than him.
5 KILL COUNT: THE PUNISHER
It's not clear what Deathstroke's kill count is but the fact that no one is keeping tabs means he's not really well known for being a mass murderer in his comic book franchise. Meanwhile, Marvel has announced that Frank Castle has already killed 48,500+ people... and counting.
Of course, there's the argument of quality versus quantity, but even the Punisher has his fair share of costumes to hang on his wall as trophies. In any case, Castle's number of confirmed kills speaks volumes about how dark and crazed his character is.
4 ARSENAL: TIE
Deathstroke is a mercenary who's proficient in many different weapons, making his choice of arms and armaments quite varied. Sometimes he might use guns, grappling hooks, or mini-bombs but his standard weapons will always be either his staff or his swords.
On the other hand, we have Frank Castle who prefers guns and as much firepower as he can pack in his human physique. Despite having less variation of tools, Castle is no slouch and even sometimes uses everything he can get his hands on as a weapon when he runs out of ammo. You can't replace that human ingenuity, it gives him a more John Wick-feel. This one's a tie.
3 EXPERIENCE: TIE
Both men can easily stand tall and proud (or even arrogant) with their achievements and accolades in their own respective comic book universe. Both also have a military background where each of them excelled in their own army divisions up until the system stopped working for them.
Moreover, the two of them have had their adequate share of superhero enemies and have also defeated beings more powerful than they'll ever be. While Deathstroke is a superhuman who has aged like fine wine, The Punisher is a dead man who refuses to die. So due to their commendable experiences, this one might as well be a tie.
2 COSTUME: TIE
Now, this one's a hard part. Deathstroke's armored ninja get-up is memorable and definitely strikes fear into the hearts of his victims assuming they see him coming. The Punisher, however, has a more epochal symbol of a punky white skull which serves as the only contrast in his all-black dread-inducing duds.
It's a tough call. Frank Castle's sense of style might be more badass, but Deathstroke's practicality and signature one-eyed assassin look is just as menacing. They both win this one.
1 WINNER: DEATHSTROKE
As for the verdict, and based on the wins, Deathstroke wins but it was definitely a close fight. Castle might get outmatched in their actual fight but he is never outgunned and will surely make Wilson sweat or even bleed. Ultimately, the supersoldier assassin from DC still wins.