Ever since its inception, the Marvel Cinematic Universe has set itself apart from other superhero franchises thanks to its ability to please audiences of all ages. MCU films are filled with exciting action and feature complex storylines to keep adults interested, but they're also accessible for younger viewers thanks to their lighthearted nature and inherent sense of fun. As we've seen time and time again in the superhero movie genre, striking such a balance isn't an easy endeavor, but Marvel Studios has pulled it off time and time again.

Still, despite its child-friendly nature, the beloved superhero franchise hasn't always been as clean-cut as one would like to think. It may be hard to believe, but throughout the years, the MCU movies have featured some surprisingly brutal moments. Whether it's a villain death or an engaging confrontation, there have been quite a few scenes spread throughout the franchise's 18 installments that would make even the darkest sequences in the DC Extended Universe seem pale in comparison. Given the MCU's lighthearted nature, though, those scenes can often fly under fans' radars. So, with that in mind, we thought it'd be appropriate to take a look back at 15 of the most surprisingly brutal/gruesome moments in the MCU (so far):

15 THE END OF THE IRON MONGER

For his first big screen adventure, Tony Stark had to fight Obadiah Stane, a former business partner who created a suit of armor of his own. Despite not having much experience wearing the high-tech armor, Stane proved to be a formidable adversary. Eventually, Stark realized he couldn't beat Obadiah on a one-on-one fight, so he came up with a plan: overload the Stark Industries arc reactor and fry Stane with it.

If that sounds particularly nasty, it's because it was. Stane was hit with the full force of the reactor, and he was essentially shocked to death. As if that wasn't enough, right after being electrocuted, Stane fell directly into the arc reactor, creating a massive explosion that almost destroyed the Stark Industries warehouse he and Tony were fighting in. As far as MCU villain deaths go, that was definitely one of the worst ones.

14 DARREN CROSS SHRINKS A MAN

Darren Cross aka Yellowjacket from the MCU

In Ant-Man, Scott Lang was pitted against Darren Cross, a businessman obsessed with recreating Hank Pym's shrinking technology. The character was incredibly ruthless, and he wasted no time in showing it. Early on in the film, Cross unveiled his Yellowjacket suit. The presentation was a success, but one Pym Technologies executive expressed doubt over releasing that kind of technology to the public.

Instead of trying to change his mind, Darren followed him into the bathroom after the meeting and nonchalantly shot the man with a shrinking gun.

Unfortunately, the gun didn't shrink the man. It turned his body into a small puddle of goo. In response, Cross took a paper towel, wiped his former co-worker off the floor and flushed him down the toilet. He then proceeded to wash his hands and carry on as if nothing had happened.

13 FRIGGA'S LAST STAND

In Thor: The Dark World, Jane Foster became infected with the Aether, an ancient power source coveted by Malekith, king of the Dark Elves. Knowing that normal medicine wouldn't be enough to remove the Aether from Jane's body, Thor took her to Asgard. Unfortunately, the Dark Elves tracked them down and attacked Thor's home world. In an effort to keep Jane safe from the invading forces, the God of Thunder placed her under the protection of his mother, Frigga.

Malekith and his servant, Kurse, found Frigga, but Jane was nowhere to be seen. Frigga battled the two villains, and despite putting up a good fight, her opponents eventually overpowered her. Malekith tried to force Frigga to give up Jane's location, but she refused, so Kurse stabbed her, leaving Thor, Odin, Loki and the entirety of Asgard in mourning.

12 ALEXANDER PIERCE'S MAID

Captain America: The Winter Soldier introduced a new villain to the MCU: Alexander Pierce, the Secretary of the World Security Council and secret Hydra leader. Throughout the film, the character was shown as a calculating individual who relied on his intellect to solve his issues. Still, being the leader of one of the biggest criminals organizations in the world, Pierce wasn't afraid to get his hands dirty, as proven when he murdered his maid.

Shortly after Captain America and Black Widow escaped from a vicious Hydra attack, Pierce called in the Winter Soldier to take care of the two rogue heroes.

Bucky visited Pierce's house, and the two started discussing a plan of attack. To their surprise, Pierce's maid accidentally walked in on their conversation. In response, Pierce picked up a gun and shot her without giving it a second thought. Yikes. No wonder he worked for Hydra.

11 THE COLLECTOR'S SERVANT

Guardians of the Galaxy introduced audiences to Taneleer Tivan, aka The Collector, an ancient being who, as his nickname implies, enjoyed collecting anything he could get his hands on, especially life forms. All the creatures he captured were kept in display boxes, except for one: Carina, who functioned as his servant. Unfortunately, the Collector was a cruel individual, and his abusive behavior toward Carina led her to an untimely death.

During the film's second act, the Guardians paid a visit to the Collector to sell him the Power Stone. Tivan offered a brief explanation of the stones and their origin, and the information caught Carina's attention. Now aware of the stone's power, she tried to use it to break free from the Collector. Sadly, the relic proved to be more than she could handle and she exploded, destroying the Collector's lair in the process.

10 CAPTAIN AMERICA AND BUCKY'S FINAL FIGHT

Putting aside its political thriller-inspired storyline, at its heart, The Winter Soldier was about the conflict between Steve Rogers and his best friend-turned Hydra assassin, Bucky Barnes. Near the end of the film, the tension between the two finally came to a head in what became one of the MCU's most brutal fight scenes to date. Following a successful invasion of the Triskelion, Rogers set out to disable S.H.I.E.L.D.'s three new helicarriers to stop Hydra's "Insight" protocol.

Before Steve could complete his mission, however, the Winter Soldier found him and the two started to fight.

To fans' delight, the Russo Brothers didn't hold back when it came to their battle. It was visceral, surprisingly brutal and most importantly, it had a strong psychological component attached to it. Steve and Bucky weren't mortal enemies fighting over the fate of the world. They were just two former friends trying to stay alive.

9 QUICKSILVER'S SACRIFICE

Scarlet Witch and Quicksilver made their MCU debut in Avengers: Age of Ultron. Unfortunately, only one of them made it out of the movie alive. The siblings started out as allies of Ultron, but their alliances shifted once they discovered his plan to use Sokovia as a meteor to end humanity. Having realized their mistake, Wanda and Pietro joined forces with Earth's Mightiest Heroes in Sokovia to defeat Ultron.

The Avengers gained the upper hand at first, but Ultron retaliated by hopping on a Quinjet and opening fire on them. Hawkeye happened to be on the robot's line of fire, but Quicksilver got in the way and took all the bullets for him. The hero's death scene was brief, but quite unnerving, as he was shown lying on the ground, covered in bullet holes.

8 GROOT AND THE TOE

Yondu, Rocket Raccoon and Groot found themselves in quite a predicament during Guardians of the Galaxy Vol. 2. At one point in the film, the Ravagers staged a mutiny. They locked Yondu and Rocket in a cell inside their ship, and kept Groot free for their own amusement. Fortunately, not everything was lost for the three heroes.

In an effort to break free, Yondu instructed Groot to sneak into the Ravagers' chambers, find his prototype fin and bring it to him.

Given the fact that he was still a baby, however, Groot had a hard time understanding what they needed, and he brought them a slew of different items. To Yondu and Rocket's horror, one of those things was a severed human toe. The movie didn't show how Groot got the toe, but the sheer image of the adorable little creature carrying a severed limb was enough to give anyone nightmares.

7 COULSON'S "END"

Phil Coulson became a fan-favorite character thanks to his supporting roles in films like Iron Man 2 and Thor. Unfortunately, his stellar tenure in the big screen side of the MCU came to an end in The Avengers. Not long after being captured by S.H.I.E.L.D., Loki staged a daring escape with the help of Hawkeye and several mind-controlled agents. Loki managed to get out his containment cell but Coulson -- armed with a Destroyer-inspired weapon -- went to confront him.

The special agent seemed to have things under control at first. However, Loki outsmarted Coulson and killed him by stabbing him in the back with his scepter. The scene was emotional, but it was also surprisingly explicit, as it openly showed the tip of Loki's scepter peeking through Coulson's chest. Given how gruesome the sequence was, it's easy to see why it almost earned The Avengers an R-rating.

6 ERIK KILLMONGER AND HIS GIRLFRIEND

Black Panther introduced one of the most intimidating bad guys the MCU had ever seen: Erik Killmonger. Putting aside his intellect and remarkable physical prowess, one thing that made Killmonger such a dangerous individual was his commitment to his cause. He wanted to rule Wakanda, and he didn't let anyone get in the way of his dream, even the woman he loved. Shortly after robbing the Museum of Great Britain, Killmonger and his girlfriend, Linda, freed Ulysses Klaue from police custody.

Once they made their escape, Killmonger turned on Klaue which prompted the villain to take Linda hostage.

To Klaue's surprise, Killmonger ended the standoff by shooting Linda. The sequence wasn't particularly explicit. However, throughout the film, Erik and Linda had been shown to have a strong relationship, so seeing him shoot her without giving the situation a second thought was, quite frankly, horrific.

5 CAPTAIN AMERICA AND IRON MAN'S FINAL BATTLE

Marvel started to lay the groundwork for Steve Rogers and Tony Stark's complicated relationship ever since the first Avengers. Both heroes respected each other, but their different points of view made them clash on quite a few occasions. Their conflict continued to grow through Age of Ultron and it finally reached a boiling point in Civil War. In the film, Stark learned that Bucky murdered his parents and Captain America had kept it a secret.

Enraged by the revelation, Tony tried to kill the Winter Soldier. Captain America stopped him and so, the two Avengers started fighting. Surprisingly, the film delivered a fight that was gritty, dirty and quite violent. Ultimately, the brutal encounter took a toll on both Steve and Tony, and even though they (somewhat) made amends by the end of the film, it doesn't look like their friendship will be the same moving forward.

4 KURSE AND LOKI

Malekith may have been the big bad in Thor: The Dark World, but he wasn't the film's only villain. The movie also introduced Kurse, a ruthless creature driven only by his desire to kill. Kurse didn't have much screen time in the sequel, but he got the chance to prove how vicious he was during the film's third act.

Following the Dark Elves' attack on Asgard, Thor and Loki traveled to Svartalfheim to confront Malekith and his army.

Once there, Thor was intercepted by Kurse, who quickly overpowered him and proceeded to beat him to a pulp. In an effort to save his brother, Loki impaled Kurse with a spear. Shockingly, the villain turned around, pulled Loki toward him and impaled him with the part of the spear sticking out of his body. Ouch. Despite its briefness, the scene became one of the most gruesome moments in the MCU.

3 NEBULA'S HAND

Guardians of the Galaxy delved deep into Nebula and Gamora's complicated family relationship. Throughout the film, Nebula made numerous references about the deep hatred she harbored for her sister. However, audiences didn't get an idea of just how much she disliked Gamora until a pivotal moment during the movie's third act. In an effort to protect Xandar from Ronan, the Guardians raided his ship, the Dark Aster.

Inside the ship, Gamora encountered Nebula and the two started to fight. Gamora gained the upper hand, and she kicked her sister out of the ship. Fortunately for the baddie, her hand got stuck between two exposed beams. Gamora came to her rescue, but instead of accepting her help, Nebula opted to chop her own hand off and escape on a Ravager ship. Thankfully, the villain's hand was robotic, so no gore or blood was visible.

2 RONAN SACRIFICES A XANDARIAN

Guardians of the Galaxy may be one of the funniest films in the MCU, but it still had its fair share of dark moments. One of the darkest ones came courtesy of the film's main villain, Ronan The Accuser. During his introductory scene, Ronan was shown arguing with a captured (and heavily beaten) Nova Corps soldier. Having grown tired of their debate, the villain lifted his hammer and crushed the soldier's head with it.

That was disturbing enough, but things got much worse.

The soldier's blood was shown running down into Ronan's sleeping quarters, implying the rogue Kree slept in the blood of his enemies. To this day, there have been very few MCU villains that have displayed the same level of brutality as Ronan, and going by this scene, we can only imagine what we should expect from him in the upcoming Captain Marvel.

1 ANT-MAN SHRINKS DOWN YELLOWJACKET

Scott Lang had a lot on his plate in 2015's Ant-Man. The former thief-turned superhero was tasked with stopping the CEO of Pym Technologies, Darren Cross, from selling his new Yellowjacket suit to criminal organizations. Following a daring heist in the Pym Technologies building, Lang successfully thwarted Cross' plans. Unfortunately, being the deranged madman he was, Cross decided to get revenge on Scott by putting on his Yellowjacket suit and kidnapping Lang's daughter, Cassie.

Lang went to rescue Cassie, but Cross proved to be a powerful adversary thanks to his advanced armor and weaponry. With no other way to beat him, Scott shrunk between the molecules and destroyed the Yellowjacket suit from the inside. Unfortunately, the suit's destruction also meant bad things for Cross, who started to shrink in on himself until finally vanishing into thin air. Yeah... that's definitely a horrible way to go.