The Supremacy System

In the Omniverse, there are 4 realms who wages war with each other in order to stand above other. Many years later they form a truce because they lost so many of their forces. In order to form a proper friendship and peace with each other find a realm that inhabitants Humans in, so beings from the 4 realms descended to the realm to bond themselves including humans. Our protagonist, Mercurius Salvatore is a youth who dream to become the strongest in the 5 realm, but many people laugh at him because he is weak while his sister and childhood friend are prodigies, but they never discriminated him, but tragedy happens when he try to save his sister and his Childhood friend during a dungeon raid and ended up sacrificing himself but fate won't let him die because of a phenomenon. Will he reach up the Top or stay a loser?