Thor is a literal diety, the closest thing comics have to a literal Super Powered Jesus. If Ragnarok is anything to go by, he's also the cutest and cuddliest Avenger. But sometimes he goes through some rough stuff -- some of it is more messed up than everything that happens to him in Infinity War.
Thor's been around for a while and he's stared down the worst terrors the Marvel Universe has to offer, but nothing really compares to the God Butcher.
Before becoming a mass murderer, Gorr was just a simple working man, living on a barren planet, trying to get by. Despite his prayers, Gorr lost his family to the harsh climate of an unforgiving world. It's hard to blame him for losing faith, for starting to believe that there were no gods.
Gorr finds out the truth the hard way when a pair of powerful beings crash-land nearby. As readers know, in the Marvel comics universe, gods do exist. They just don't care about barren planets or the hapless souls who live on them. And that sets Gorr off.
Stealing an unstoppable uberweapon called the Necrosword from one of the fallen gods, Gorr begins a spacefaring rampage, basically becoming an intergalactic serial killer. We see the future, where Old King Thor is the last one living on Asgard, facing down a neverending horde of Gorr's shadow monsters.
Thor only has a chance at winning when he teams up with his angsty young self, his crusty old self and three of his future granddaughters, and even then it's a dicey situation. Because this is an ongoing superhero comic you know Thor has to win, but that doesn't mean the events of the story can't shake the hero to his core.
Though Gorr is eventually defeated, his distrust of gods lingers in the back of Thor's mind. This comes to a head a couple years later when Nick Fury (who is now an all-knowing superbeing named the Unseen -- long story) tells Thor that Gorr was right all along: Gods aren't worthy of their power at all.
Thor does a facepalm so hard that he drops Mjolnir and hasn't been able to pick up since. As of this writing, that was four years ago. Four real human years since Mjolnir has been wielded by the hairy Asgardian. Since then Thor has had an arm cut off, Asgard died again, his mommy and daddy both got sick and then mad at him, Jane Foster developed cancer, and before he could even prove himself worthy of Mjolnir, it got thrown into the heart of the sun.
And that's not even the end of Gorr's corrupting influence. A short story showed a possible future where the Necrosword still exists, and later consumes Galactus.
There's killing half a world's population, and then there's literally cutting a world in half.
Asgard, the eternal home of Thor and the rest of the gods, is destined to end in Ragnarok. That's okay because as we saw in the movie, Asgard isn't a place, it's a people. Except Asgard keeps dying, and everyone keeps going with it.
There have been roughly as many Ragnaroks as there have been Civil Wars in the Marvel comics universe. That's chill and all, since the cycle of death and rebirth is inherent to Norse mythology. But then there was Siege. Upending the cycle completely, Norman Osborn (aka the Green Goblin) and his Dark Avengers just demolished Asgard completely.
Of course, since he was publicly "reformed" at this point during the comics, Osborn needed an excuse for his Siege. So he lured Volstagg into a fight with some knock-off villains, during which Osborn destroyed a stadium full of people, making it look like Volstagg was the one who did it.
For a batshit supervillain, Osborn has pretty sound reasoning for thinking this would work. He figures that a similar inciting incident set off Civil War, so killing a bunch of innocent civilians should work here too!
To his credit, it works wonders. Most of the world is fine with Osborn going to town on Asgard, which is floating outside a small town in Oklahoma (again, long story). The Dark Avengers chop off limbs left and right, murdering indiscriminately. They can pull this off in part thanks to Sentry, who's more or less Superman level in power. To make matters worse, Sentry has an evil, repressed side of himself called The Void. Put together an incredible power with a bloodthirsty split personality, and well, say goodbye to Ares.
Believe it or not, this is the part where Loki finally has a crisis of conscience. Seeing that Asgard is being obliterated in part thanks to him, Loki fights back against Sentry -- only to get obliterated himself.
Sentry/The Void eventually turns back into his alter ego, a small, sad man whose wife was killed by Osborn. Filled with grief and rage, Thor agrees to put the sad man out of his misery.
Oh, but it only gets worse from here.
So this one is technically about Loki, but it hurts Thor more than anyone else. We all know Loki is a bad dude, but Thor can't help but love (or at least, really like) his adopted brother. So let's keep that in mind going forward.
One thing that you might have guessed by now is that Loki always has a plan. As it turns out, Loki had hoped that the events of Siege would help make Asgard stronger, because while being cute and cunning, Loki ain't actually that smart. After all, Asgard was destroyed and so were scores of Asgardians, including Loki himself. Loki had arranged it so that the Book of Hel is wiped away, leaving it so that Loki can never go into the underworld, and therefore has to be reborn. And then, evil Loki is gone forever. Sort of.
And so the God of Mischief Loki is reborn as a young trickster... child. Thor eventually finds a boy who seems to have no memory of his heritage. Kid Loki is born.
Kid Loki is still a little scamp, but that could be easily chalked up to being a teenager. Though his motivations are still unclear, Kid Loki seems to have a purer heart than any previous incarnation of the character. Unfortunately, it is soon revealed that the rebirth of Kid Loki was all a secret plan by Evil Loki. By manipulating his naive younger self, Evil Loki wipes Kid Loki's soul away and steals the child's body. And pretty much gets away with it.
The heartbreaking part is that Kid Loki sees it all coming, but is powerless to stop it. All he can do is say goodbye.
For awhile, Loki tries to be better -- contending against a future Loki who is trying to make sure Loki stays evil -- but eventually the world blows up, Loki turns evil again, and now the world is ending (again). A Loki who shredded a child's soul to slightly manipulate the people who loved Loki? I hope those aren't Infinity War 2 spoilers.
It might be easy to miss, but that's Ragnar0k with a zero instead of an O. This time we're not talking about the mythic destruction of Thor's homeworld, but about the evil robot clone of Thor called Ragnarok. RoboThor came about during the Civil War comic event, which you might be able to guess is already a pretty big sign something messed up is about to happen.
See, Thor wasn't around during the time of Civil War, but Tony Stark thought he could really use a big-leaguer like the God of Thunder to fight on the side of superhero registration. Apparently the Fantastic Four, Spider-Man, and everyone in the government wasn't enough. In order to take down a very strong man who throws a shield, Tony decided to recreate a god. But instead of a full-on clone, with his own memory and soul, Ragnarok-bot was more of an undead magical slave that Tony could bend to his whim. Kind of like a Roomba with death vision.
And since this was Civil War and Tony was doing a thing, it all ended quite terribly. One of the biggest deaths of the entire series came when Ragnarok fought and killed Goliath.
There's technically a canonical reason why the Thor-bot went so haywire it killed a guy (Hank Pym helped create the robot, and Hank Pym was secretly a Skrull at the time), but all that really matters here is that Hercules eventually destroyed the impostor.
When he finally came back, Real Thor was none too happy about what had happened in his absence. Though Thor and Tony slugged it out, because it's comics the fight was forgotten within half a year.
But don't worry, fans, Thor got his revenge against Rangarok after the robot was brought back as one of Norman Osborn's Dark Avengers. Ragnarok died only to come back as one of Norman Osborn's Dark Avengers. We know we're repeating ourselves; not so sure Marvel knew.
Volstagg is known as the cutest and nicest Asgardian. He's a big fat guy with a red beard -- he looks like the prequel to Santa, and acts like it too. Volstagg stands as friend to everyone and everything, except healthy foods. He eats like he breathes and fights like he eats and drinks like he fights, and has always been an all-around large, awesome dude.
And then the War of the Realms comes. It's basically Marvel attempting to make their fairies and trolls look cool by recreating Viet Nam. This brings out the darker side of some characters -- Volstagg in particular goes a bit Full Metal Jacket.
See, Volstagg is helping children escape from the war when he -- and the children -- are attacked. And just totally, totally beat down. Volstagg survives, with lots of wounds, because he's a God. The kids? You know that black stuff you scrape off the grill? Yeah, basically that.
Due to all the kid dust, Volstagg kind of loses it. Though he's a god, he's not on the level of Thor or anything, so his rage is containable. That is, until Volstagg finds a Mjolnir from a dead universe, which transforms him into the bloodthirsty War Thor. Imagine if Hagrid had the personality of the Hulk and wielded a giant sledgehammer -- it's about as awesome as it sounds.
While he can take down pretty much everyone, Volstagg... well, takes down pretty much everyone, becoming the same type of terror that drove him to become War Thor in the first place. That includes innocent families like the same ones he's supposedly avenging. (Aw, look, a message!)
Eventually Volstagg gets beat almost to death, and is then reduced to what he was before -- a man, wracked with grief and terror, covered in the guilt of his failure to protect the children counting on him.
But uh, Thanos dusting Spider-Man for a year before he inevitably comes back is kind of sad too.