Detention Sphere is a rare Enchantment card from RNA Guild Kit (GK2), collector number 10. Current market price: $0.49, TCGplayer market prices via Scryfall.
When this enchantment enters, you may exile target nonland permanent not named Detention Sphere and all other permanents with the same name as that permanent. When this enchantment leaves the battlefield, return the exiled cards to the battlefield under their owner's control.