Complex sentence: The Ancient Kharlan War was caused by magitechnology, which consumes vast amounts of mana; by splitting the world in two halves and having them vie for the small amount of mana, Mithos effectively stopped the creation of magitechnology and a second cataclysmic global war.
Split into simpler sentences: The Ancient Kharlan War was caused by magitechnology, which consumes vast amounts of mana. By splitting the world in two halves and having them vie for the small amount of mana, he effectively stopped the creation of magitechnology and a second cataclysmic global war.