Thanos's reputation has been given a massive boost by the MCU but he's always been one of the greatest villains in the Marvel Universe. A fearsome and powerful foe to all who battle him, Thanos truly made an impact with Infinity Gauntlet and since then, he's become one of Marvel's most popular villains, his mystique built up by sporadic appearances.
He's gotten a lot more exposure in recent years, which has a lot of fans wondering about him and his origins, especially his ties to the Eternals, one of Jack Kirby's greatest creations. He and the group are inextricably linked in many ways.
8 He's Extremely Intelligent Like Other Eternals
Eternals live for a very long time and as such, are quite intelligent. Even the "dumbest" Eternal is still vastly more intelligent in some way than even the smartest humans, as they can spend millennia learning about a subject. That's one of the best parts about living for so long; anything one wants to know is a simple matter of study and they have all the time in the world, literally.
Thanos is one of the smartest villains in Marvel Universe. He knows secrets that few others are privy to and he's used his knowledge to carry out some deadly attacks over the years. Thanos is known as a dangerous and powerful foe but he also should get credit for just how smart he is, as he can easily outsmart most of Earth's greatest scientists.
7 He Has A Wide Variety Of Powers Like Other Eternals
Eternals are known for having many powers. While each of them has a specialization, Sersi manipulates matter, Druig controls minds, and Makkari runs fast, they also have all kinds of other powers. Most of them can fire powerful energy blasts, they're all invulnerable to most attacks, have super strength and durability, and can fly. All these powers have served them well in their years battling the Deviants.
Thanos shares this in common with other Eternals. He's amazingly powerful, to the extent that he rarely has to use all of his powers. Because of his hatred for his people, and every other living thing in the universe, he's enhanced his powers, so he has all the typical Eternal powers at greater levels than can be imagined as well as the ability to channel cosmic energy and nearly unmatched mental powers.
6 He Has The Longevity Of An Eternal
The Eternals came into existence over a hundred thousand years ago, created by the Celestials to protect the planet Earth from the Deviants or any other threats. They were created to last the test of time and as such the Eternals live up to their name, as they are untouched by the ravages of the time or disease. It is impossible for an Eternal to die of old age and they will always appear in the flower of youth if they want to.
Thanos, as an Eternal, also shares this long life with them. While his looks were impacted by the Deviant gene he carries, he's still basically timeless at the point he's at right now and has been shown to exist countless years into the future. Thanos is just as Eternal as his fellows and will live for as long as the universe shall last.
5 He Resurrects Easily
The Eternals can't die of old age or disease and are remarkably tough. They're impervious to most kinds of harm but that doesn't mean they can't be hurt or killed. A powerful enough foe can wound or kill an Eternal but luckily, that's not the end for them. The Celestials gave them a mechanism for returning to life called the Machine, which regenerates an Eternal according to specifications stored inside it, even allowing them to make cosmetic changes to their bodies.
Like many other Marvel villains, Thanos has died many, many times over the years. Luckily for him, resurrection is basically written into his genetic code. Thanos can be resurrected by the Machine, like other Eternals, or with numerous other methods, as has been shown over the years. This makes Thanos a great threat, as his foes never know when he'll come back.
4 They're The First People He Committed Genocide Against
Thanos is one of those characters who has been through a lot over the years and it all stems from his early days in the Eternal colony of Titan. Because of his looks due to the Deviant gene, his mother tried to kill him not long after he was born. As he grew up, his fellows on Titan treated him terribly because he didn't look at them and cast aspersions on his parentage and who he was.
This had a profound effect on the young Thanos. A straight line can be drawn from the way his people treated him to the nihilism and genocide that would define his later life. Once he was old enough, he left Titan, returning years later as commander of a pirate fleet, unleashing a devastating attack against the Eternals of Titan using thermonuclear weapons that killed scores of them.
3 He's From The Eternals Colony Of Titan
In the beginning, there were only a hundred Eternals. A schism formed between Zuras, the leader of the group, and A'Lars, a popular Eternal. A'Lars wanted to experiment on Eternals and make them capable of having children, while Zuras and his cadre believed the Celestials made them perfect as they were. After a short but fierce battle, A'Lars and his faction left the Earth and moved to Saturn's moon, Titan.
This is the origin of Thanos, as A'Lars would meet with fellow Eternal exile Sui-San on Titan and after experimentation, they'd have Thanos and Eros. His life on Titan wasn't happy and those torments are what transformed Thanos into the monster he would one day become.
2 He Was Recently Resurrected By Phastos
With Eternals coming to the MCU, Marvel put another Eternals comic, by superstar writer Kieron Gillen and amazing artist Esad Ribic. The first story arc began with the Eternals hunting the murderer of their leader Zuras and finding Thanos in one of their abandoned cities. They battled him twice, defeating him the second time and learning how he returned: Phastos resurrected him to use as a weapon after discovering a terrible secret about the Eternals.
Gillen set out immediately to clear up the water surrounding Thanos's Eternal origins, linking him to the group immediately. A one-shot called Eternals: Thanos Rising was put out, where Gillen and artist Dustin Weaver recounted the origin of the Titanian Eternals and Thanos, as the Mad Titan would be playing a huge role in the series.
1 He Is An Eternal
The biggest link between Thanos and the Eternals is the simplest one: he is an Eternal. While he's not one of the original Eternals created by the Celestials, nor is he from the Earth, he is an Eternal through and through. Beyond the Deviant gene, he has all of the characteristics of being an Eternal, from the powers to the longevity to the ability to be resurrected by the Machine.
Thanos is easily the most powerful of that storied race due to his enhancements and it remains to be seen how he will affect them since they've returned to prominence in the Marvel Universe.