Which MCU villains are still alive and could return as part of Marvel's Phase 4? Although the Avengers aren't known as killers, the reality is that not many of their enemies survive. Back in 2008, Tony Stark blazed the trail when he and Pepper conspired to kill Obadiah Stane, and since then the Avengers have typically operated with lethal efficiency. Where the comic book iterations of the Avengers frequently agonize over the choice to kill, the big-screen versions don't pull any punches.
Of course, death is no real barrier to a villain's return. Some of Marvel's movies are out of sequence; as a result, Captain Marvel will explore the backstory of Ronan the Accuser, the deceased villain from Guardians of the Galaxy. Plus, Avengers: Endgame is expected to involve an element of time travel, and is rumored to involve deceased foes like Frank Grillo's Crossbones. And these are comic book movies, which means resurrections can't be ruled out; in the comics, Wakanda in particular is known for an enchanted altar that can be used to raise people back from the dead, which means characters like Killmonger and Klaue could still potentially return to haunt Black Panther.
But, assuming the dead stay dead, which villains could come back to plague Earth's Mightiest Heroes in Phase 4 and onward? Discounting Michael Keaton's Vulture (already confirmed for Spider-Man: Far From Home) and Hannah John-Kamen's Ghost (who seems to have been redeemed after Ant-Man & the Wasp), here's a complete list.
Tim Roth played Emil Blonsky in The Incredible Hulk, a semi-deranged soldier who had himself transformed into the Abomination - a monstrous being who almost defeated the Hulk in one-on-one battle. The World Security Council viewed Blonsky as a hero, and even attempted to coerce Nick Fury into making him part of the Avengers Initiative. He's reportedly held in cryogenic suspension in a cell in Alaska; given Blonsky was imprisoned by S.H.I.E.L.D., it's entirely possible he was broken out during the Hydra uprising in Captain America: The Winter Soldier.
Batroc the Leaper
A French-Algerian mercenary, pirate, and martial artist, Batrox the Leaper is a classic Captain America villain. He's best known as the bad guy who gets hired to slow the superheroes down while his employers get away with stolen goods; Batroc doesn't plan to win, he plans to lose with style. The MCU version was introduced in Captain America: The Winter Soldier, when he was secretly hired by Nick Fury to capture a S.H.I.E.L.D. mobile satellite platform launch ship, the Lemurian Star; Steve Rogers led the mission to recapture the Lemurian Star, and Batroc put up a surprisingly good fight. He was imprisoned, but it's not hard to envision a scenario where he's gotten out of jail - perhaps even legally, by serving his time.
Perhaps the greatest cosmic threat out there is the Dread Dormammu, the other-dimensional entity who rules the Dark Dimension. Dormammu is eager to expand his reign into our dimension; he was defeated in Doctor Strange, where the future Sorcerer Supreme forced him to swear never to attack Earth again. But let's face it, nobody expects Dormammu to abide by that promise; in fact, he made a similar vow in the comics, and he found his way around it many times. It's possible Doctor Strange 2 could introduce Doctor Strange's sorceress girlfriend Clea, and she's actually Dormammu's niece - which means the sequel could return to the Dark Dimension.
Thor: Ragnarok introduced the Grandmaster, a cosmic being who delighted in setting up gladiator matches where warriors fought to become his champions. His operation on Sakaar was overthrown, and he's fallen on hard times, as detailed in the MCU tie-in novel Cosmic Quest Vol. 1, in which the Grandmaster went to visit his brother the Collector. According to Jeff Goldblum, the Grandmaster survived Thanos' snap, and he's still at large.
Page 2 of 3: Other MCU Villains That Can Return In Phase 4
Played by Daniel Brühl, the MCU's version of Baron Zemo was introduced in Captain America: Civil War. A Sokovian citizen turned terrorist, Zemo was devastated after his family was killed during the Battle of Sokovia. Until Thanos, he was the only villain in the MCU to fully achieve his goal, succeeding in tearing the Avengers apart. The MCU portrayal is very different to the original comic book iteration, and it raised a few eyebrows as a result. But the fact Zemo survived means Marvel could yet develop him in a more faithful direction; with the introduction of the Ghost in Ant-Man & the Wasp, Marvel has now introduced two characters who are associated with the Thunderbolts. Could Zemo return in a Thunderbolts project?
Former CEO of Hammer Industries, industrialist Justin Hammer was one of the major villains in Iron Man 2. Hammer considered himself Tony Stark's biggest rival, and did everything he could to find ways around the Iron Man technology. "I wanna make Iron Man look like an antique," he complained in one key scene. Hammer wound up incarcerated in Seagate Prison, but his company is still heavily invested in developing enhanced weapons. The first season of Luke Cage introduced the Judas Bullet, a Hammer-tech weapon designed to neutralize even enhanced beings like Luke Cage.
Karl Mordo is pretty much guaranteed to return. Chiwetel Ejiofor played the sorcerer in the first Doctor Strange film, a student of the Ancient One who trained alongside Stephen Strange. Mordo disagreed with Strange's methods, though, believing that there is a price for magic. Doctor Strange's post-credits scene saw Mordo decide there are too many sorcerers, and launch a campaign to drain all the magic out of the world - presumably adding the magic he stole to his own power. He's been clearly set up for Doctor Strange 2.
The Incredible Hulk also introduced Samuel Sterns, the man destined to become the Leader, played by Tim Blake Nelson. A scientist who was fascinated by Bruce Banner's Gamma-irradiated DNA, Sterns' open head wound was exposed to Banner's blood, and he underwent a swift mutation. The character's largely been forgotten in the MCU since 2008, with the official comic book tie-in Fury's Big Week revealing he was captured by S.H.I.E.L.D.. Kevin Feige has suggested he's well aware that fans feel this is a missed opportunity, but it's a matter of "just finding the right place." For all that's the case, though, Marvel isn't going to be making any more solo Hulk films anytime soon, so the odds of the Leader's return are pretty low.
The Mandarin and the Ten Rings
The Mandarin twist in Iron Man 3 was particularly unpopular with comic book fans, who were shocked that the iconic Iron Man villain had been turned into something of a fake-out. Marvel produced a one-shot, All Hail the King, that revealed Trevor Slattery was unwittingly impersonating a man who really does exist in the MCU, and that the Mandarin was singularly unimpressed by Slattery's pretense. The "real" Mandarin is still out there, the criminal mastermind behind a terrorist group known as the Ten Rings, and he could potentially return one day. The only question is whether or not Marvel will wish to revisit one of their most controversial plot twists, or whether the MCU has simply moved on too far.
Page 3 of 3: Even More MCU Villains Who Can Return In Phase 4
The Red Skull
Captain America's greatest foe, the Red Skull led Hydra to greatness during WWII, but was ultimately defeated and apparently killed at the end of Captain America: The First Avenger when he held the Tesseract. Avengers: Infinity War revealed that he'd survived, transported to the distant world of Vormir instead. He's lived for decades on Vormir, his soul ravaged by proximity to the Soul Stone, transformed into something less than truly human. With the Soul Stone now taken by Thanos, the Red Skull no longer has a role on Vormir, and he could conceivably head off-world.
The Red Skull could potentially be one of the most dangerous villains in the entire MCU. Not only is he intimately tied to two Infinity Stones, but he also had a copy of the Asgardian Book of Yggdrasil - a sacred tome that explained the Infinity Stones, and may have contained other cosmic secrets. He's presumably still a super-soldier, although he's no longer truly human, more like a wraith than a living being. Given the Soul Stone has feasted on his soul for decades, it's possible the Red Skull can no longer die. What's more, it wouldn't necessarily be too difficult for him to get back to Earth; the Thor films have confirmed that the cosmos is riddled with portals, some of which were known to Loki and the ancient Asgardians. The knowledge from the Book of Yggdrasil could help the Red Skull use these portals.
Spider-Man: Homecoming introduced a number of potential Spider-Man foes, with Michael Mando playing Mac Gargan - a brutal crime boss who, in the comics, became the cybernetic killer known as the Scorpion. He was featured in the ferry sequence, when he attempted to buy advanced tech from the Vulture gang, and wound up in prison. Gargan returned in Spider-Man: Homecoming's post-credits sequence, imprisoned along with the Vulture, who he attempted to threaten in the hopes of learning Spider-Man's true identity. It's generally believed Marvel has plans for Scorpion down the road, although he's not been confirmed to return in Spider-Man: Far From Home.
In the MCU, Bokeem Woodbine played the second incarnation of the Shocker, Herman Schultz. Another member of the Vulture Gang, Schultz was given powerful vibrational gauntlets - and proved pretty dangerous in using them against Spider-Man. He was captured with the help of Ned Leeds, and is currently behind bars; it's certainly not hard to imagine the Shocker returning in a sequel, perhaps working with the Scorpion next time.
Related: Casting the Sinister Six For the MCU
Will Thanos survive Avengers: Endgame? The Mad Titan is the Avengers' most fearsome foe, and in Avengers: Infinity War he successfully achieved his insane goal of erasing half the life in the universe with a snap of his fingers. The film ended with Thanos retiring to live as a farmer, satisfied with this "achievement," but he's certain to return in the fourth Avengers film when Earth's Mightiest Heroes attempt to either undo or avert the Decimation. If Thanos survives this clash, then he could still remain a force to be reckoned with in the MCU, perhaps even resuming his career as a dangerous warlord.
Michael Chernus was introduced as the Tinkerer in Spider-Man: Homecoming, a member of the Vulture gang and a tech expert who's been working with advanced/alien technology for several years. Although Spider-Man took down the Vulture, the Tinkerer remains at large. Given Spider-Man has a large number of villains who use this kind of tech - cyborgs like Scorpion or villains who use technology like Mysterio - he could be a key figure going forward.
A ruthless and genocidal artificial intelligence created by Tony Stark in Avengers: Age of Ultron, the Avengers think Ultron has been completely destroyed. Tony Stark personally supervised the destruction of every single piece of Ultron technology, believing that the AI's code could repair itself if just a fragment survived. But here's the catch; Stark didn't do a particularly good job. Spider-Man: Homecoming revealed that the Vulture had acquired Ultron tech, and there could conceivably be more out there. The threat of Ultron is dormant - but not gone.