Yu-Gi-Oh!: Ultimate Duelist

Decades ago, many creatures of all shapes and sizes suddenly appeared on the Blue Planet, causing global panic and causing a sharp decline in the number of humans. At the same time, many creatures chose to join the human side to help people defend their homes. Slowly, humans discovered that both the invading creatures and the creatures that helped humans could be turned into cards, making it more convenient for humans to use. Gradually, as the invading creatures were basically wiped out, humans were able to summon the monsters in the cards to fight. As time went by, people gradually built a complete duel system. At this time, a senior gamer on Earth...