Marvel has treated readers to the greatest battles imaginable. The clashes between the heroes and villains have captured the imaginations of fans like few others. Oftentimes, the drama of the Marvel Universe can pivot upon mistakes made by the characters. Sometimes, the heroes make choices that allow the villains the other upper hand. Other times, they do things that make things worse.
Even the villains have made mistakes that destroyed their chances at victory. These mistakes have informed many tales. They've shown that Marvel's characters are fallible and made things more interesting, creating narratives that grab readers and don't let go.
10 Thanos Cost Himself The Infinity Gauntlet
Infinity Gauntlet is a Marvel event blockbuster. The battle between Thanos and the denizens of the Marvel Universe was intense. With the omnipotent and omniscient power of the Gauntlet on his side, Thanos ran through everyone who came after him, but he lost his power source because of a very dumb mistake.
After defeating Eternity, he took the being's place as the embodiment of the universe, leaving his comatose body with the Gauntlet in easy reach of Nebula. Thanos had been torturing her since he got the Infinity Gauntlet, so she grabbed it off his body and took his power. Thanos would have won if it wasn't for this foolish mistake.
9 Trusting Beast As Leader Of X-Force Has Been A Disaster
With the establishment of the mutant nation of Krakoa, an intelligence service was needed. That's where X-Force came in. Wolverine was made field leader, but Beast was the overall commander. This seemed like a good idea, but it's proven to be a huge mistake. The first cracks showed in how he dealt with Terra Verde, trying to use their telefloronic technology.
This plant-based tech was suborned by citizens of Terra Verde and almost used against Krakoa. Since then, Beast has made more terrible decisions, committing atrocities and creating a black site space station for experimenting on prisoners. He made Wolverine into a mindless killer, which caused him to kill a US general and get caught on surveillance cameras. It's a complete disaster.
8 Mindwiping Scarlet Witch's Memories Of Her Children Had Disastrous Consequences
Scarlet Witch's marriage to the Vision saw her eventually create children for the two of them. The problem was that she stole pieces of Mephisto's soul to do so. This caused a whole kerfuffle, and Scarlet Witch's memory of them had to be wiped from her mind. This huge mistake led to her losing her mind and attacking the Avengers.
This attack cost Scott Lang, the Vision, and Hawkeye their lives, destroyed Avengers Mansion, and endangered New York City. The Avengers should have either had a professional like Xavier mindwipe her or just not bothered, allowing her to come to terms with the loss. This would have saved a lot of trouble later.
7 Xavier And Magneto Keeping Moira MacTaggert Secret Opened Up A Whole Can Of Worms
X-Men history is full of momentous events, with the establishment of Krakoa being a big one. It was all made possible by Magneto and Xavier working with Moira MacTaggert behind the scenes. Her mutant reincarnation powers gave them the information they needed, but they kept her secret from their fellow mutants, faking her death and hiding her mutant status.
Keeping this secret was a massive mistake. Mystique and Destiny went after her, depowering her, but were forced to let her go. She was able to get a powerful cybernetic body and took her mutant cure, from her second life, to Orchis. It also caused everyone to stop trusting Xavier and Magneto, costing them power in the country they created.
6 Xavier Mindwiping Everyone Of His Actual Second X-Men Team Had Devastating Consequences For The Shi'Ar
Many Marvel leaders aren't trustworthy, something Professor Xavier has proved many times. When the original X-Men were captured by Krakoa, with only Cyclops escaping, Xavier went to Moira MacTaggert and asked to use her students – Vulcan, Darwin, Petra, and Sway – to rescue them. They failed, with Vulcan and Darwin surviving unbeknownst to everyone and Cyclops escaping again.
Xavier decided the best way to fix this was to mindwipe everyone. Vulcan would eventually escape, trying to take revenge, and then went after the Shi'Ar. He became Emperor and got them embroiled in war after war, costing countless lives and wrecking the Empire, all because Xavier decided to hide his fate instead of trying to help him.
5 Allowing Norman Osborn Power Over The Thunderbolts Facilitated His Takeover Of The Superhero Initiative
Norman Osborn hasn't just been Green Goblin, becoming Iron Patriot after he was made head of the Superhero Initiative and the Avengers. His Dark Reign was nearly disastrous. It all happened because Iron Man found Osborn useful during the superhero civil war, using him to fight against Atlantean assassins, sent after Iron Man because of the death of Namorita.
After Iron Man won, he rewarded Osborn by making him the head of the new Thunderbolts. This put Osborn in the battle against the Skrull infiltrators and allowed him to kill Skrull Queen Vernake. Iron Man was deposed because of his mistakes and Osborn was put in charge.
4 Iron Man's Entire Reign As Director Of SHIELD Was Mistake After Mistake
The Avengers aren't perfect, something underlined by Civil War. The whole conflict could have been ended by some talking, but instead, they went right to fisticuffs. It ended with Iron Man as Director Of SHIELD, which just ended up being a huge mistake. Iron Man was more inclined to go after his friends than investigate the secrets of SHIELD that he had discovered while a member of the New Avengers.
Iron Man made so many mistakes as Director. The Skrull secret invasion was made worse by how badly he bungled things, he never actually caught any of his former friends, and he alienated Thor by creating Ragnarök. Iron Man is easily the worst SHIELD Director in recent memory.
3 Legion Accidentally Killed His Father And Caused The Age Of Apocalypse
Legion's relationship with his father, Professor X, was always strained. Legion decided that was because of Magneto, so he decided to go back in time and kill Magneto while the two men were working together in Israel. Several X-Men piggybacked with him and tried to stop him, but they failed miserably. As Legion was about to kill Magneto, Xavier jumped in the way.
The death of Xavier in the past created an entirely new timeline, one where Apocalypse took over the US and Magneto formed his own team of X-Men to battle him. Millions of humans died in this alternate universe. While the timeline was fixed, Legion caused a terrible death for countless innocents.
2 Scarlet Witch Depowering The Mutants Could Have Been Stopped By Not Being So Secretive
The X-Men's status quo has changed many times, with the most jarring being Scarlet Witch depowering the mutant race during House of M. However, this entire thing could have been avoided if not for one huge mistake – not inviting Quicksilver. Pietro spied on the meeting between Xavier, the X-Men, and the Avengers, and that spurred him to take action.
Giving Quicksilver a say in his sister's fate would have been a smarter choice. He could have said his piece and worked with the two teams, instead of against them. A lot of tragedy would have been avoided if they had done so.
1 Doctor Doom Saved The Multiverse Where The Illuminati Failed
The Incursions were Marvel's greatest catastrophe. The Illuminati came back together to stop them, but their only solution was destroying alternate Earths as they careened towards the 616 Earth. This didn't work at all, as it didn't stop the root causes, and ended with the destruction of Earth.
While they were doing that, Doctor Doom found a way to gain godlike power, saving as much of creation as he could. The Illuminati acted like villains, whereas Doctor Doom did what heroes usually did. They destroyed, and he preserved. Sure, he still made himself God, but his actions were more heroic than the Illuminati's.