The Puzzlegate

At the beginning of your turn, add a time counter
to The Puzzlegate.
{t}, sacrifice The Puzzlegate: Search your library
for an artifact, with a converted mana cost equal
or less than the amount of time counters on The Puzzlegate, and put it onto the battlefield. Then, shuffle your library.
Nobody has seen what's behind it, but whatever it is,
it's magical energy signature is strong.