Atlantis, the Dragon City

While a monster that mentions "Atlantis, the Dragon City" is on the field, reduce the Levels of all monsters in both players' hands and fields by 1. If you Link Summon a "Daedalus" monster, you can reduce the material requirement listed on it by 1 and Link Summon it with 1 less material. If this card is in your GY and you control "Umi": You can place this card face-up on your field. You can only use this effect of "Atlantis, the Dragon City" once per turn.