Previous Versions can be found here.

Slowing was added during the Beta 3.4 update as a replacement for Sharing to fit more with the rework of the Patience. It puts a paralyzed enemy monster back into its owner's deck when used and it will cost 4G more to place it again. Because of this it's suggested that people keep 2 or 3 of this card in their decks and save them for later in game when the opponent places more expensive cards on the field.

Keep in mind that it cannot be used on your own monsters, which you shouldn't do anyway, but it also doesn't stack on the same enemy monster.