If the target creature becomes an illegal target, the Equipment remains on the battlefield unattached.
Mind Carver
Attaching an Equipment with its enters-the-battlefield triggered ability isn't the same as using its equip ability. You don't pay mana for the attachment, and if the Equipment enters at a time you couldn't cast a sorcery, you can still attach it to a creature you control.
An ability that offers a bonus if an opponent has eight or more cards in their graveyard won't provide additional benefits if more than one opponent has eight or more cards in their graveyard. There are also no additional benefits no matter how many cards are in an opponent's graveyard, as long as there are at least eight.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Scott Murphy
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
