Alchemist's Vial

Oracle Text

When Alchemist's Vial enters the battlefield, draw a card.

1, T, Sacrifice Alchemist's Vial: Target creature can't attack or block this turn.

Card Rulings

6/22/2015 Activating the last ability of Alchemist’s Vial targeting a creature that’s already attacking or blocking won’t cause that creature to stop attacking or blocking. It will prevent that creature from attacking or blocking in any additional combat phases the turn may have (although this is unusual).