Hysterical Blindness

Instant

Creatures your opponents control get -4/-0 until end of turn.

"The panic is amusing, but the real fun comes when the spell passes and the villagers start looking for a scapegoat."
—Ludevic, necro-alchemist

2011-09-22 Hysterical Blindness's effect will continue to apply to a creature even if you (or a teammate) gains control of that creature later in the turn.
2011-09-22 Only creatures controlled by your opponent when Hysterical Blindness resolves will get -4/-0. Creatures that enter or that an opponent gains control of later in the turn will be unaffected.

mtg.wtf