I think, there should be a separate game. Campaign, for the individual story how Fortune Fighters are in Multiplayer and Multiplayer for the real gaming experience.

Campaign would have introductions about the ancient artifacts that the Gods bestowed for the fighters to protect from the willy nilly enemy teams from the north, south, east and west. Each enemy team has its own name based on what location they are, either north, south, east or west. You will be trying to protect the artifacts instead, you were tempted by the hidden treasure that the Gods forbid to open the gate by joining the artifacts from each location. You will be in chage in getting the artifacts, meeting different characters helping and guiding you to the artifacts heavily guarded by the ancientt elementals, golems, slimes, spiders, creeps etc. There will be 5 artifacts, the mystic artifact, the plague artifact, the static artifact, the lava artifact and the soul artifact. The 5th is the soul of a person who was destined to bring the artifacts in to place near the temple of the hidden treasure.

Thats what I thought