The Path To Revenge: tournament arc

In the year 1888, a man who saved over five countries became the male monarch and brought peace for many years. As time passed the king was assassinated, later on his death the lands he ruled fell into ruins. The King had four sons that detested each other. The brothers fought each other to decide, who the next King is. Every time they fought all the outcomes were draws. Soon the masses who were loyal to them, joined in. The small fight slowly grew into a war that split the five countries into four. While the fifth country became a refugee camp that called "Gemini", and just like the brothers the four countries hated each other. As time passed the brothers then died from old age. In the year 2056, the brothers' war still remains. A group of 4 people must ban together to prevent an impending apocalypse from destroying everyone in. The leader of the group is a 18-year-old teenager named, John Spencer. Who only wants one thing, revenge and end this war?