Honkai Impact 3: Become the Captain of the Knight King and Travel Through the World

At the beginning, he was reborn in the pre-collapse civilization and was rescued by Ellie. With the help of the system, he gained the power of the Kamen Rider during the battle. After the Final Battle, he became the captain on his own and traveled to various anime worlds after the end. [Note] There may be a harem in this book