Description by couchtuner for Avengers Assemble Secret Wars Season 4 Episode 1 : As the Avengers find a way to return Iron Man to their reality without bringing Ultron along, they managed to prevent Ghost from stealing Stark Industries technology at the Stark Expo. After swiping the prototype Arc Reactor, Leader head to the Wakandan Consulate to steal the Vibranium there with his army of Humanoids. When a guilt-ridden Thor helps Black Panther take down Leader when the Avengers arrive, Leader summons his new incarnation of the Cabal (consisting of Arnim Zola, Enchantress, Executioner, and Kang the Conqueror) to fight the Avengers while taking advantage of Iron Man not being there.
Watch It Here : Avengers Assemble Secret Wars Season 4 Episode 1 Avengers No More Part I