If One with the Multiverse leaves the battlefield and later returns to the battlefield (or you play a second one), it's considered a new object and you may cast a spell using its last ability regardless of whether or not you did so earlier this turn using the enchantment that was on the battlefield before
In fact, players usually spend the gold, get the cards, and dont even play because of these low rewards
Other permanents, such as creatures, can't be attacked
Even better, each Draft Booster display comes with a Realms and Relics Box Topper card
Credit: Wizards of the Coast Lazav, Wearer of Faces FromTheShire: Really wish this wasn't until end of turn
Nine-Fingers Keene may as well have Hexproof, given 9 life is a lot