Beatrix, Vexing Interrogator

Whenever an enchantment enters the battlefield
under your control or is put into your graveyard,
investigate.
{t}, Sacrifice three clues: draw three cards, then
each opponent puts the top X cards of their
library into their graveyard, where X is the
number of cards in your hand.
"Come, unburden your mind. The less you know,
the better." —Beatrix