I Became a Necromancer, but Accidentally Became an NPC

In a world with more civilizations and races, because the destructive power of their weapons was too powerful, each race suffered heavy losses of varying sizes 1,000 years ago. In order to reduce losses, each civilization and race finally chose to travel through the game world of previous civilizations to "peace" the war. Being strong in the game can lead your own civilization to become stronger. Whether a civilization is strong or not is completely bound to the strength of the tribesmen in the game.