Forum:My explanation theory

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The War that Shook the Earth
The mushroom war has happened in the the future, hees how i layed it out:

The mushroom war began with a world threatening communist dictatorship from the future Soviet Russia. Similar to the reign of adolf hitler, russia was rallied into an idea to take over the world. Bombing raids were scattered all over Eurasia. Many smaller countries were in confusion and inmatched decision against these unexplained attacks. Rusians probably used high technology artillery alien to us, maybe like the UFOs from the rainicorn-dog wars.

Later, when america joined the war, the tension was starting. Before it was called the Mushroom War, the war was probably called World War III or something. Though because the russian "hitler" was restless, a primary war has turned into a nuclear war, World War becoming Mushroom War. Both Union Allied and Soviet countries are all trying to overpower and threaten each country will more and more nuclear artillery. Eventually the imprope use of nuclear plants have tripled, and nuclearic chemicals have started mutating and polluting wildlife and even mankind. Restless the countries have become and bombs have fallen everywhere, devastating people, destroying cities, and mutating the world like never before. Large amounts of nuclear chemicals also damages climate change, and the world has become colder and colder in the north and hotter in the South. This explains the Ice Kingdom, which could be the leftovers of a European country (Ice King has a slight scandinavian accent). And the Candylands could be post-war Germany, since PB is known to speak German. The Humans are now endangered.

The Survival
Well how do you explain the survival of wildlife and fableheim? Similar to the the path of Moses, The Cosmic Owl, sent down from Mars, probably led the animals to some magical oasis, like the the Rim of Heaven, to escape the ice age!( I'll explained the ice age later.) That may sound weird, but guess how they got Buddhist/Christian-like beliefs! Outside the "oasis" the Ominus Bomb has fallen blowing of the entire landscape of the future East Pacific, and almost all humankind have died or mutated. Rainicorns ate the remains of dead humans.

The Rainicorn-Dog Wars
The Dogs though, lost companions of the humans, needed a home. the Crystal Dimension their best option. The Rainicorns of the Crystal dimension, however, did not want to share territory with the Dogs, and sought war against them. The Dogs, dependent on survival, had no choice but to fight back, armed with leftover technology from their nearly-exctinct human friends had no choice but to fight back. this started the Rainicorn-Dog Wars. (The Dogs most likely won the war, due to the fact that dogs survived, but i do not own Adventure Time, so tell me if anything has changed.)