Steel and Gunpowder: the Godslayer's Eternal War

This book is mainly about a modern man who crashed in a plane and landed in a different world. He gained the ability to summon historical armies and control mobile islands, and thus rose up in a fantasy world with low demons in the early stage and high demons in the later stage. His path went from military conquest for survival to the battle of killing gods, and he was forced to face the huge paradox of becoming a god. Time travel + system flow + farming competition + fantasy epic