Number Guardian
Number's Guardian (ナンバーズのガーディアン Nanbāzu no Gādian) are the spirits of the "Legendary Number" cards in the Number's Ruins within the Yu-Gi-Oh! ZEXAL anime, assigned with the duty of protecting them. In order for a Duelist to obtain their cards, he or she must Duel against their respective guardian to see if he or she is worthy of wielding the "Number". After a guardian is defeated, they disappear usually. They, also, are related to Legendary Figures or the card instead.