They simply go to the bottom of their owners library, and although might seem too much, you can do it for a single if miracled
Phyrexian Cards There are two Phyrexian cards in Kamigawa: Neon Dynasty
The most important thing to remember are: a creature with power equal or below 0 does not deal any damage
The added upside of slowing down decks that pay life is pretty neat, and it takes an otherwise debatably playable card (wiping only at sorcery speed) into a place where some decks will happily consider it
The choice of these specific FINAL FANTASY titles, VI, VII, X, and XIV, appears to be a thoughtful approach, aiming to resonate with a wide spectrum of the FINAL FANTASY fanbase, from those who grew up with classic 16-bit adventures to players currently exploring vast online worlds
One more oddity, how many other equipment have no equip activated ability