Malfnir Spy

At the beginning of your upkeep, put a sleuth
counter on Mafnir Spy.
At the beginning of each opponent's upkeep,
look at the top X cards of that player's library,
where X is the number of sleuth counters on
Malfnir Spy. You may then put any number of
those cards on the bottom of their owner's library
and the rest on top in any order.