Baron Zemo (2010 Marvel Animated Universe)

Baron Helmet Zemo is a major antagonist who appeared in season 3 of Avengers Assemble (entitled Ultron Revolution).

He was voiced by David Kaye, who also voices his alter-ego Citizen V.

Background
He is the son of Hydra scientist, Baron Heinrich Zemo, who had previously fought Captain America in World War II, and the former leader of his own supervillain organization, the Masters of Evil.

History
As the son of Hydra's leading scientists and commanders, Helmet Zemo sought to carry his father's legacy and recreate the super-soldier serum. Zemo attempted to formulate his own version of the serum, but it was imperfect, leading his test subjects to turn into hulking abominations.

Now in his elderly years, Baron Zemo is resolved to find his father's perfected serum, as he brainwashes Captain America to lead him to an old Hydra castle while he relives the moment of fighting his father there, alongside the aid of Bucky Barnes. Zemo soon makes his appearance before Iron Man and Black Widow, after they discovered Captain America's disappearance, and introduces himself to them. He then injects two of his Hydra soldiers beside him with his imperfect serum, mutating them as they soon fight the two Avengers, while Zemo continues to follow Captain America into the castle. Zemo is finally lead to his father's laboratory, where he finds his father's serum and injects himself with, rejuvenating him. Once Iron Man and Black Widow find Zemo after defeating his mutated Hydra agents, they discover him in his new state as he now dons a mask. Zemo then battles the two and overcomes them with ease until Captain America joins the fight after he breaks free of his mental control. As they battle outside of the castle by a cliffside, Zemo fires his pistols at the castle's walls, causing it and the cliffside to crumble. Baron Zemo goes after the super soldier serum after it fell from him and towards the cliff, but Captain America grabs his hand as he tries to save him. However, Zemo refuses his help and instead falls into the water below, as he wishes to maintain his father's legacy. After the heroes get to safety, Iron Man scans the cliffside, showing that Zemo had only disappeared.

Baron Zemo later recruits the Masters of Evil after he teleported them to his base from their previous defeat with the Avengers and appointed himself as leader. He then creates a diversion to lure the Avengers to his base located in Brasil while he leads the Masters of Evil to Avengers Tower. However, once they take over the tower's systems and begin their raid, they discover Hawkeye as the only member there and assaults him.