Taking a page out of the DC Comics Flashpoint event, which saw the DC Comics universe flipped upside down, the Alex Luthor YouTube channel does a similar routine with the MCU.
Check out the awesome "Avengers Flashpoint Paradox Fan Trailer" feauring a plethora of what-ifs in the Marvel Cinematic Universe including Captain America Hydra.
Alex Luthor also came up with a cool backstory for the Avengers Flashpoint Paradox with blame lying on none other than Scarlet Witch!
Little information about the story: Scarlet Witch is the reason why this alternate universe thing happens. Captain America and here are the only ones that know that everything is changed. Captain America wakes up in his doppelganger’s body, and he learns that Hydra has won World War 2, and his version of this reality actually helped Hydra win the war and conquer the world. Hydra is now and Empire, and Tony Stark is the emperor.
Wakanda is one of the only places on Earth isn’t part of the Hydra empire, and Black Panther leads his people in a war against Tony and his Hydra army.
Mutants and super powered beings are being hunted by Hydra. Magneto is the leader of the resistance. Wolverine is part of the resistance too, but he was captured. Black Widow is a resistance spy that infiltrated Hydra, she is married to Captain America, and she is on a mission to kill him (the evil version of Capt). Both Spider-Man and Rhodey are part of the resistance and they stole suits and armor from Stark. Hulk is red and he is the Doomsday weapon for Hydra. Bucky is an assassins for Hydra. Loki rules Asgard, while Thor is missing. Ultron is actually something of a Vision in this reality, and he is not evil or good, he is on his own side.After learning all this, Captain America tries to find Scarlet Witch, who is missing in this new reality. What will happen? Find out in 2017…