“He Who Remains”-Kang, won the “Kang-War” and, in order to make sure it couldn’t happen again, prevented other Kangs from ever coming into existence. He did this by controlling each universe (the multiverse), and had all of them follow a general guideline. So every universe was different, but not too-different as to create another Kang-variant. However, after Sylvie (from the Loki series) killed HWR-Kang, there was no one to keep the multi-verse from branching out too-much and thus, other Kang-variants began to reappear. Once again though, a Kang decides to kill universes and prevent the destruction of the multi-verse. (I think this Kang was going to follow the path of HWR-Kang, and create something similar to the “Time-Authority”, and prune universes in-order to keep the multi-verse safe). This is the Kang we see in Ant-Man. However, Janet Van Dyne was able to interfere in his plans which resulted in the Ant-Man movie. Since Ant-Man killed that Kang, the one who was probably going to become “He Who Remains Pt.2”, he broke the cycle of, “One Kang wins the war and prevents any others from appearing for the safety of the multi-verse”, so now the Kang-variants are free to run rampant. I think that’s the story up to this point. Now, I speculate that the Kangs will cause trouble for the next couple movies, but will then begin to cause incursions, universes colliding into each other, gradually increasing in occurrence until the multi-verse is destroyed. These incursions will lead to secret wars, Dr.Doom will hopefully appear sometime during this, and the movies will essentially follow the comics. I think the only difference will be that instead of the “Beyonders” causing the incursions, it’ll be directly due to the Kang-variants traveling too much, but still, Dr.Doom will create the Secret Wars and it’ll end with Reed fixing everything.