Deadpool might have his fair share of comedic moments in the Marvel universe, but the mercenary's powers allow him to be one of the strongest Marvel characters, proficient enough to defeat and kill major Marvel heroes ranging from Captain America to The Fantastic Four.
With Ryan Reynolds and Hugh Jackman announcing the collaboration of Deadpool and Wolverine in Deadpool 3, it is highly likely that Deadpool and Wolverine, the two poster boys of the healing factor, would face off just like they have done in comics. Deadpool often relies on his swords and firearms skills as well as his strategic creativity to go against such powerful characters.
The Fantastic Four
The aptly titled miniseries Deadpool: The End finds Deadpool mobilizing an offensive against the of the Fantastic Four by reversing their own powers against them.
So, while Susan Storm loved staying incognito with her invisibility powers, Deadpool ensured that she loses them and becomes everyone's center of attention with the social burden eventually killing her. Similarly, the Human Torch burns to death while the Things turns into a liquid. Lastly, Mr. Fantastic gets turned into glass (and then shattered into pieces). This mass murder of the team shows how Deadpool is more than just a funny sadist; his actions are planned and come out of his specific observations of the superhero team's strengths and weaknesses.
Wolverine
Even though Wolverine bears similar powers as Deadpool (the same healing factor most importantly), the Merc-With-A-Mouth's mind can work in creatively disturbing ways, strong enough to take down one of the most powerful mutants of Marvel Comics.
In the disturbingly dark miniseries Deadpool Kills the Marvel Universe, the antihero ditches his usual katana for a carbonadium sword with the metal strong enough to render Wolverine's healing factor useless. The subsequent duel results in Deadpool effortlessly slicing his opponent to death. This death is notable as only a few characters have been able to defeat Wolverine to death given how the adamantium-clawed mutant has virtually been immortal due to his healing factor. It is yet open to interpretation if carbonadium can affect Deadpool's own healing factor. But for now, Deadpool calls the shots no matter how powerful Wolverine and his claws might be.
Captain America (Clone)
In Deadpool Vol 4 #28, the man in red gets to engage in a hand-to-hand combat duel against a clone of Steve Rogers AKA the original Captain America. Mimicking the same powers as the Avenger, the clone puts up a tough fight, but Deadpool eventually had the upper hand when he relied on his guns.
After an endless exchange of fatal punches and headbutts from both sides, the mercenary finally put his finger on the trigger and let his rifle blast the clone's head! Mirroring most of his original's powers, the Captain America clone retains the enhanced strength that stems from the Super Soldier serum. So, in a way, Deadpool inflicting damage on a Super Soldier's clone displays another feat of strength on his part. He doesn't even rely on cunning or any cheat codes this time; he wins the bout by sheer brute force.
Punisher
Quite a master trickster when it comes to his homicidal plans, Deadpool can also rely on the help of other Marvel characters as can be seen from his killing of the Punisher. In Deadpool Kills The Marvel Universe, he purposely lures in Frank Castle by letting the Puppet Master pose as him.
When Castle shoots down Puppet Master (disguised as Deadpool) from a long-range sniper rifle, he rushes to have a look at his kill. His shock on finding Puppet Master comes to Deadpool's advantage who strikes him from behind and shoots him in the head, one of his most preferred killing methods. Punisher could have been killed at Deadpool's hands easily given how after all, he is just a human with no superpowers. But Deadpool still relying on deception to take him down shows that he loves innovating his kills. The artwork by Dalibor Talajic obviously adds further to the terror and shock value with readers getting a rare glimpse of fear on Punisher's face.
Daredevil
Marvel's anthology comic series Contest of Champions was quite an amusing product of its times. Back in the 1990s, it was quite common for comics to feature iconic duels and let the readers decide the outcomes through the voting system. One such fight comes from 1999's Contest of Champions Vol 2 #4 with Daredevil facing off Deadpool in a storyline titled "The Final Cut".
The protector of Hell's Kitchen is mostly known for his moral righteousness and his willingness to save civilians no matter how dangerous the situation might be. Deadpool takes advantage of his niceness by throwing a baby at him. When Daredevil rushes to save the baby, he lands in a dumpster and realizes that the child was a decoy, a Deadpool doll instead! The surprised vigilante is held at gunpoint by Deadpool who scores an easy victory. Yet again Deadpool wins due to cunning and studying his enemies. An adversary like Punisher would have still not been this empathetic, but he knew the guilt-burdened and ever-responsible Daredevil's conscience would get triggered if he throws a baby. It is a cheap (yet effective) batle trick.
The Watcher
Uatu, the Watcher is one of the eternal cosmic beings in Marvel who knows of the entirety of all timelines, merely observing the events of the comic book universe as they unfold. However, in Deadpool Kills The Marvel Universe, the blabbermouth mutant manages to pull off an unpredictable move taking even the Watcher by surprise.
With Deadpool literally "watching the Watcher", Uatu comes into shock and is easily overpowered by Deadpool who uses a taser and his usual katana to good use. It doesn't take much time for the surprised Uatu to give up easy with Deadpool neatly chopping off his head. Uatu might not be the strongest character in the Marvel Universe, but he is definitely an all-knowing figure who can call the shots. But Deadpool doesn't even want his powers of seeing all timelines; he just kills him for the sake of it (like other characters in the miniseries). By defeating an unarmed Uatu, Deadpool shows his barbarism and also acquires an almost god-like status.
The Hulk
The green gargantuan creature known as the Incredible Hulk is arguably one of Marvel's most terrifying characters thanks to his immense muscular strength. Deadpool once encountered him in the 1997 title Deadpool Vol 1 #4, eager to collect his blood sample after he himself is affected by gamma radiation.
Convinced that Bruce Banner's blood can save him, Deadpool decides to engage his monstrous alter ego in direct conflict. As Banner turns into the Hulk and jumps in the air eager to crush the mercenary below, Deadpool very conveniently places a spiky post below, impaling the Hulk once he lands on the ground. The entire moment plays out in a darkly slapstick fashion but highlights the power of brain over brawn. Capable of crushing his bones or tearing him in half (even though Deadpool's regenerative powers would ensure survival), the Hulk is just eager for a short-term victory while Deadpool plans for a goal that would surprise and injure his gigantic foe.
Doctor Strange
Most of Deadpool's victories over the strongest Marvel heroes and villains come from Deadpool Kills The Marvel Universe. But while the comic details his kills in a brutally explicit fashion, his encounter with Doctor Strange makes for an open-ended situation.
The readers don't know how exactly did Deadpool manage to murder the Sorcerer Supreme. All that they see is a featuring a dead Strange laid out on a table in his Sanctum Sanctorum. Deadpool's weapon of choice is the Japanese throwing weapon known as the sai as it can be found protruding outside Strange's chest. While the events preceding the death aren't revealed, it is clear that even Strange's spells were of no use to stop Deadpool who might have surely relied on some strategy to render his mysticism useless. Once the magic is limited, Strange would obviously be no match to the brutally strong Deadpool.
Old Man Cable
Deadpool's encounters with Cable range from friendly to violent and include a lot of multiple timelines. In Despicable Deadpool, the mercenary partners up with Cable to take on an evil Cable clone known as General Stryfe.
When both agree that "the heart" of yet another version of Cable would satisfy Stryfe and fulfill a deadly contract, Deadpool sets off to take on Old Man Cable. Aged but still powerful (much like Old Man Logan, the visceral futuristic version of Wolverine), Old Man Cable still doesn't pose to be a major threat to Deadpool who shoots him right in the face and cuts out his heart which he eventually stuffs inside a pillowcase. Despite his age, Old Man Cable still retains his superhuman strength and cybernetic enhancements. But this quick death shows that Deadpool doesn't even wish to give his enemies a chance to display their powers. Without wasting time, he just lets the bullets do the talking.
Thanos
Be it in the comics or the Marvel Cinematic Universe, Thanos has established his reputation as one of the most menacing villains, thanks to his control over the Infinity Stones. However, with a few more enhanced powers, the indestructible antihero managed to vaporize the Mad Titan!
The encounter takes place in Deadpool vs Thanos #4 when the two get into a tussle while rescuing Madame Death from Thanos's brother Eternity. To take on Thanos, Deadpool receives help from the cosmic entity known as the Uni-Power which turns him into an alternate version of Captain Universe. Gifted with his newfound powers and abilities, Deadpool wastes no time in taking down Thanos. Deadpool taking down Thanos makes for a historic moment but also shows that maybe, he might not have defeated the world-destroyer on his own. Using the powers of Captain Universe proved to be a major cheat code for the mercenary.
