Whenever another nontoken creature enters the battlefield under your control,
investigate (To investigate, create a colorless Clue token. It's an artifact with ", Sacrifice this artifact: Draw a card.").
, Sacrifice X Clues: Target opponent reveals the top X cards of their library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield under your control. That player puts the rest on the bottom of their library in a random order.