Marvel villains who are scarier than Thanos
Elle Collins

Thanos is the villain that the Marvel Cinematic Universe has been building to since Avengers, and by the time he fully arrives on the scene in Avengers: Infinity War, he's as big as promised. Once he assembles all the Infinity Stones into his Infinity Gauntlet, he has the power to wipe out half the lives in the universe, and he does exactly that. Obviously, this will somehow be dealt with in the upcoming sequel, but that won't change the fact that Infinity War has the most unsettling and tragic ending of any superhero movie, and that's all the Mad Titan's doing.
So, where can you go after Thanos? Once you've had a villain who can kill half the universe with a snap of his fingers, what chance does any other villain have of being that scary or threatening? Well, that really depends on what you're afraid of, but there are certainly some villains from Marvel Comics who can give Thanos a run for his money when it comes to being frightening. Let's take a look at some of them.
Hela

Sure, Thanos killed half the universe, but he did it in the pursuit of what he saw as a higher purpose. Hela doesn't need a reason to kill. Death is who she is and what she does. Literally, she's the Norse Goddess of Death. When she kills you, you don't go on to any sort of just reward, either. If you're taken by Hela, you go to her realm of Hel and become part of her undead army. As afterlives go, it doesn't sound particularly fun. This is why Vikings are so motivated to prove their value as warriors, because only the bravest and best are chosen by the Valkyrie to spend eternity feasting in Odin's great hall of Valhalla. Everyone else, in theory, goes to Hel.
The Marvel version of Hela (renamed from the Norse Hel to differentiate the goddess from the realm) was introduced by Stan Lee and Jack Kirby in Journey into Mystery #102. She wears the intricate armor and multi-horned helmet we associate with Kirby designs, but in dark green and black, it's a far more intimidating look. Of all Thor's enemies, she's perhaps the scariest. It's hard to stop someone from killing whoever they want, after all, when they rightfully have dominion over the realm of death.
Galactus

Whether Galactus should be considered evil is the subject of some debate, both inside the Marvel Universe and in the real world. What's much more clear is that evil or not, he's terrifying. It's not that Galactus wants to hurt you. In fact, he doesn't care about you at all. He's a godlike space giant, and as such you're basically a bug to him. The problem is that Galactus is hungry, and only one thing can satisfy his hunger. To sustain his immortal life, Galactus eats entire planets, and you never know when he might choose yours.
Galactus first arrived to consume the Earth in Fantastic Four #48, also by Stan Lee and Jack Kirby. As Lee explained in the introduction to Marvel Masterworks Fantastic Four Vol. 5, which collected that story, he and Kirby came up with Galactus because they'd created so many increasingly powerful villains that a god seemed like the obvious next step. So far, Galactus has been deflected every time he's tried to devour the Earth, usually by the super-brain of Reed Richards, leader of the Fantastic Four. He keeps coming back, however, and if he ever catches Reed and the other heroes off guard or busy with something else, that'll be it. No more Earth.
Elle Collins

Thanos is the villain that the Marvel Cinematic Universe has been building to since Avengers, and by the time he fully arrives on the scene in Avengers: Infinity War, he's as big as promised. Once he assembles all the Infinity Stones into his Infinity Gauntlet, he has the power to wipe out half the lives in the universe, and he does exactly that. Obviously, this will somehow be dealt with in the upcoming sequel, but that won't change the fact that Infinity War has the most unsettling and tragic ending of any superhero movie, and that's all the Mad Titan's doing.
So, where can you go after Thanos? Once you've had a villain who can kill half the universe with a snap of his fingers, what chance does any other villain have of being that scary or threatening? Well, that really depends on what you're afraid of, but there are certainly some villains from Marvel Comics who can give Thanos a run for his money when it comes to being frightening. Let's take a look at some of them.
Hela

Sure, Thanos killed half the universe, but he did it in the pursuit of what he saw as a higher purpose. Hela doesn't need a reason to kill. Death is who she is and what she does. Literally, she's the Norse Goddess of Death. When she kills you, you don't go on to any sort of just reward, either. If you're taken by Hela, you go to her realm of Hel and become part of her undead army. As afterlives go, it doesn't sound particularly fun. This is why Vikings are so motivated to prove their value as warriors, because only the bravest and best are chosen by the Valkyrie to spend eternity feasting in Odin's great hall of Valhalla. Everyone else, in theory, goes to Hel.
The Marvel version of Hela (renamed from the Norse Hel to differentiate the goddess from the realm) was introduced by Stan Lee and Jack Kirby in Journey into Mystery #102. She wears the intricate armor and multi-horned helmet we associate with Kirby designs, but in dark green and black, it's a far more intimidating look. Of all Thor's enemies, she's perhaps the scariest. It's hard to stop someone from killing whoever they want, after all, when they rightfully have dominion over the realm of death.
Galactus

Whether Galactus should be considered evil is the subject of some debate, both inside the Marvel Universe and in the real world. What's much more clear is that evil or not, he's terrifying. It's not that Galactus wants to hurt you. In fact, he doesn't care about you at all. He's a godlike space giant, and as such you're basically a bug to him. The problem is that Galactus is hungry, and only one thing can satisfy his hunger. To sustain his immortal life, Galactus eats entire planets, and you never know when he might choose yours.
Galactus first arrived to consume the Earth in Fantastic Four #48, also by Stan Lee and Jack Kirby. As Lee explained in the introduction to Marvel Masterworks Fantastic Four Vol. 5, which collected that story, he and Kirby came up with Galactus because they'd created so many increasingly powerful villains that a god seemed like the obvious next step. So far, Galactus has been deflected every time he's tried to devour the Earth, usually by the super-brain of Reed Richards, leader of the Fantastic Four. He keeps coming back, however, and if he ever catches Reed and the other heroes off guard or busy with something else, that'll be it. No more Earth.