Travel Diary in Another World

The male protagonist was originally a normal person on the earth. One day, he gained a very powerful power and began to adventure in various dimensions. Because he was too powerful and had no rivals, he became empty and depressed. Finally, one day he found the meaning of continuing to take risks. He sealed his power and came to another world to adventure again. Here He met some people and became involved in their stories. This adventurous journey seemed to have no destination. Every country he visited would experience wars and disputes. He saw the evil and kindness of human beings. More importantly, he met Irena on the witch's journey... I wonder if we can go together on the journey. The new story has just begun...