As a result of Hawkeye and Falcon being transported to Vanaheim, two Shadow Nyx have appeared in Manhattan and the rest of the Avengers must keep them from draining Earth's energies. Now Doctor Strange and the remaining Avengers must find a way to defeat Agamotto. Marvel travel to an icy asteroid to rescue Thor from the Enchantress. After the Avengers take down some of his followers, Tiger Shark makes his way to the embassy's cultural art gallery to steal a jar for his mysterious benefactor. Anyhow, he destroys only 95% of Ultron, being emotional about Arsenal and Ultron is able to reboot and defeat Tony. After phase-shifting Seeker, Ultron begins his next plot to eliminate humankind where he ends up using Black Bolt as a power source.
After helping Captain America take out Crossbones, T'Challa makes off with Captain America's shield claiming it was stolen property. Now Black Panther and Hawkeye must put aside their differences and past grudges in order to stop Madame Masque. The visions of Loki lure Thor, Hulk and Hawkeye into the chambers of the Learning Games where failure is a one-way portal to Valhalla. Now Iron Man and Doctor Strange must put aside their differences in science and magic in order to reclaim the Eye of Agamotto and defeat Dormammu before he makes plans to conquer Earth and other dimensions. Their fight takes them to the Blue Area of the Moon where the allows the Avengers to use his base to find out what they need to know about Thanos.
When the reassembled Panther Key is stolen during a blackout, M'Baku escapes from his cell as White Wolf has his own plans to keep the Panther Key safe which conflicts with Captain America and Black Panther's plans for it. Under Captain America's suggestion, Hawkeye puts Ant-Man through an Avengers training course on Monster Isle to determine if he is cut out to be a member of the Avengers. They find Captain America alive, but Vision discovers that he is a robot sent by Red Skull, who called the New Avengers for help when his new A. Impossible Man even does various things to improve the movie. Stark must motivate a local pacifist Rock Tribe to take action. Seeing the fall of the Avengers, Black Widow uses the power of the stones. Every superhero began to conduct its own war for justice.
Thor must team up with this timeline's to defeat Doctor Doom and undo the time change that Doctor Doom committed. This is a brand new season of Avengers Assemble with a new type of animation. Later he claims he was suspicious and hence he did not share the details. Songbird joins the original Avengers when she realizes that this isn't what the right thing to do is. Afterwards, Ultron takes control of Avengers Tower and Iron Man's Hall of Armors.
Due to T'Challa's grandfather T'Chanda making them do a promise to him, Black Bolt and Medusa are reluctant to give up the claw piece of a key. He identifies the mysterious person as who plans to take back the Eye of Agamotto and cleanse all of Earth of it's chaos. Unfortunately, Arsenal gets possessed by who uses Arsenal's absorbing powers to take the power of the Infinity Gauntlet for himself. Captain America and Black Panther head to Hong Kong where they find Baron Mordo working on the Talisman of Kaluu. While making their way to Asgard, they must avoid Executioner, Ulik and a fellow Rock Troll , and a group of Asgardian Goblins. They run into Black Panther's adopted brother who is said to have a supposed list of known Shadow Council operatives. Meanwhile, Tony seeks new challenges for the team.
They start with T'Chanda's grave where Black Panther uses the Crown to learn about his grandfather's past that involved T'Chanda, Captain America, and Peggy Carter dealing with an exchange of Wakandan technology between Hydra operatives led by Baron Heinrich Zemo and Arnim Zola and the Shadow Council. Of course this proves to be a problem when arrives on Earth to get revenge on Odin. After Wakanda is further developed by Bashenga, Bask is still hooked on the red core as she wants to use its powers on the Atlantean raiders and other enemies of Wakanda. Following Baron Mordo's defeat, the mysterious person who trapped him in another dimension needs help seeking Doctor Strange as Captain America and Black Panther give him a ride back to the Avengers Compound where Doctor Strange suddenly attacks them. Once they do with their equipment with them, Klaue double-crosses Black Panther when shows up to give Klaue his sonic emitter back in exchange for his help to get into Horizon High.
As Black Panther chases after him, they are attacked by and his mercenaries who have allied with the Shadow Council. The Avengers discovers they are more than eight heroes. Ultron then goes to destroy humans when the Avengers go to battle him. Before they can take them to a safe location, Thanos returns and takes control of them. Meanwhile, earthquakes occur on Earth as the result of Earth and Asgard being pulled towards each other by the Space Infinity Gem which is in Loki's possession. The Avengers attack Ultron and fail to stop him.
Before Bask can have Black Panther executed, White Wolf rescues Black Panther and they run off with Ulysses Klaue as their hostage. With Wakanda on the threat of sinking and Bask having sacrificed her life to stop the laser, Black Panther now must use the Crown to save Wakanda. They encounter , , and along the way. Note: does a voice cameo of an army general. Marvel a tour of Avengers Tower, they end up dealing with Iron Man's old enemy whose awakened Inhuman abilities have enhanced his phasing abilities as he plans to steal Friday while disabling each of the Avengers one by one.
Things become even more difficult when the Avengers discover the Squadron Supreme's last few plots were all part of an even bigger plan to revive their previously unknown sixth member named. In addition, Tony also mentions that the nations of the world have pledged unity against Wakanda including Atlantis. While the Avengers and the New Avengers fight an army of Mindless Ones, Doctor Strange and Jane Foster's Thor form rescue Thor even when Loki unleashes the All Dark. She allies herself with Zarda and in a plot to spring all the inmates at the Vault. While trying to retrieve Heimdall's sword from K'un-Lun, Black Panther and Falcon team up with to overcome Dracula who was possessed by the enough to make him immune to sunlight and his vampires.
Note: Pertinent information found in comments. Captain America discovers that the trespasser is none other than his old partner now the Winter Soldier who is back seeking revenge on Red Skull. The Mighty Avengers then decide to join the original Avengers when one of their own is forced to be registered. While giving Inferno and Ms. Thor promises that if he can't prove the good he does on Earth, he'll return home forever.