Red Skull

The Red Skull is a character appearing in the Marvel Cinematic Universe, based on the Marvel Comics character of the same name. He is the "Big Bad" of Captain America: The First Avenger, where he is played by Hugo Weaving, and also has cameos in Avengers: Infinity War and Avengers: Endgame, where he is played by Ross Marquand.

History
Dr. Johann Schmidt was born in Germany to Hermann and Marta Schmidt, likely between 1896 and 1900. Much of his early history is unknown, but he developed a fascination with Norse mythology at an early age, and by 1930 he was a Professor at Friedrich Wilhelm University in Berlin. Dr. Schmidt foresaw the rise of the Nazi party and allied with them, it seemed that Hitler shared his passion for Norse folklore. But this alliance was only a means to an end - his true loyalties lie with a secretive, ancient order known as HYDRA. Schmidt was recruited into the SS in 1934, advancing to the rank of Lieutenant General. One of his first assignments was to hunt one of his former colleagues from FWU: Professor Abraham Erskine. Professor Erskine had made some groundbreaking research on genetic engineering and was rumored to have been working on a serum that could enhance human strength and endurance to superhuman levels. But he had no interest in giving this formula over to the Nazis. Neither, it turned out, did Schmidt; he sought the formula for himself. After forcing Erskine to finish the formula, he took a sample of it himself. It granted Schmidt superhuman strength, but it came at a terrible cost: He would lose his hair, his skin became deep red, and his facial features deformed to the point they resembled a demonic skull. After defecting to the United States, Erskine would suggest the serum did not actually disfigure Schmidt... it simply brought his true self out: "Good becomes great, bad becomes worse."

Schmidt hid his disfigurement under a lifelike mask that resembled his original face, and was placed in charge of his own weapons research division, which he named HYDRA, after his secretive order, with a fortress in the Alps. On some level, Schmidt realized this was an exile, as his grotesque visage meant he no longer met the Führer's "standards of physical perfection". He became obsessed with finding the Space Stone, which he knew as the Tesseract, as he had learned that Odin had hidden it on Earth centuries ago. In 1942, he finds it in a monastery in Tønsberg, Norway and brings it back to his base. He has a Swiss bio-physicist, Dr. Arnim Zola, analyze it, and they are able to use the Tesseract to power several high tech weapons. He shows several of these weapons to impatient SS inspectors who are eager to see results, then kills them when they see that he intends to target Berlin when the Allies are defeated. He learns that Erskine is working on a new version of the Super Soldier Serum with the Americans called Operation Rebirth. He sends an assassin, Agent Kruger, to sabotage the project. Kruger assassinates Erskine, but not before injecting the serum into one successful test subject, a "kid from Brooklyn" named Steve Rogers.

In 1943, a HYDRA base in Italy is discovered by the 107th Infantry Division, led by Sgt. James Barnes. The HYDRA forces, armed with superior weaponry, defeat them and Barnes is captured. Rogers, now wearing an experimental suit of armor designed by Howard Stark and operating under the name Captain America, leads a team to rescue Barnes, where he encounters Schmidt for the first time. Schmidt reveals his true Red Skull visage and taunts Rogers, before setting the base on self-destruct and making his escape. At this point he appeared to stop masquerading as a normal human and began openly operating as the Red Skull.

For the next two years, Captain America would become a persistent thorn in the Red Skull's side, as he would locate and shut down several HYDRA bases. By 1945, the Red Skull was prepared to initiated his endgame, Project Valkyrie, a devastating aerial attack against the United States. Captain America fought his way to the Red Skull's plane and the two had their final showdown. During the confrontation, the Skull attempts to draw upon the power of the Space Stone, but ends up disintegrated by its power. Cap, and the rest of the world, presumed him to be dead.

But in truth, the Red Skull was teleported to the distant world of Vormir, where he became the guardian of the Soul Stone. Since the Soul Stone could only be attained by someone who was willing to sacrifice someone who was dear to them, a sociopath like Schmidt had no hope of claiming its power and hence was its perfect guardian. Now an omniscient, wraith like figure, he found some small amusement in seeing people trying and failing to claim the stone. Eventually, "Thanos, Son of A'Lars" arrived on Vormir, and the Skull saw him succeed where others failed, sacrificing his daughter Gamora and claiming the stone.

After the Avengers defeated Thanos, Captain America would encounter the Red Skull one last time when he returned the Soul Stone to its original resting place. Whether the Skull was able to recognize his old nemesis is not entirely clear.

Powers and Abilities
As a result of Professor Erskine's super soldier serum, the Red Skull possessed superhuman strength, endurance, and durability. His reflexes were similarly enhanced, giving him cat-like agility. His punches could dent steel, and he could run at a foot speed of 25 miles per hour over short distances. He had a genius level intellect, which was also enhanced by the serum. He was a highly skilled marksman, favoring his sidearm in combat situations.

As the Stone Keeper, the Red Skull had ironically acquired the immortality he sought while he was on Earth, at the cost of becoming a wraith-like figure that was, arguably, no longer human. In seventy years, the only signs of aging he had was his skin being a bit paler, and this could be attributed to the darker atmosphere of Vormir, which was on a fixed orbit that permanently blocked light from its sun. He also had a degree of omniscience, able to instantly deduce the identities of those who came to Vormir seeking the Stone, and who they were descended from. Black Widow is particularly surprised when he refers to her as "Natasha, daughter of Ivan" as she did not even know her father's name prior to that point.

Quotes
"Tomorrow HYDRA shall stand master of the world, borne to victory on the wings of the Valkyrie. Our enemies' weapons will be powerless against us. If they shoot down one plane, hundreds more shall rain fire upon them! If they cut off one head... Two more shall take its place! Hail HYDRA!"

- Captain America: The First Avenger

"My weapons contain enough destructive power to decimate every hostile capital on Earth. Quite simply, gentlemen, I have harnessed the power of the gods."

- Captain America: The First Avenger

"You could have the power of the gods! Yet you wear a flag on your chest and think you fight a battle of nations! I have seen the future, Captain! There are no flags!"

- The Red Skull gives Cap the obligatory "Join the Dark Side" speech

"A lifetime ago, I too sought the stones... I even held one in my hand. But it cast me out, banished me here, guiding others to a treasure I cannot possess."

- Avengers: Infinity War