Ode to Humanity: Earthlings, Rise!

Fifty years ago, Dracon City fell into another dimension. Despite having to fight and defend themselves alone, they held fast to the banner of Earth and stood tall against the terrifying Exbeasts found within the Altermension.
Fast forward to the present day, Meng Chao was reborn. Much to his surprise, he found out that he could become stronger by contributing to society. He then decided that he would become the most powerful of them all, wipe out every single Exbeast, and conquer the entire Altermension.
His ending, his parents' ending, and even the ending of all mankind; he swore to rewrite them all!