Arn, The Ageless Prankster

When Arn, The Ageless Prankster enters the battlefield, you may reveal three cards from your
hand at random.
{t}, discard a revealed card: Randomly search your library for a card with a converted mana cost
equal to or less than the discarded card's, shuffle
your library. If it costs 3 or less, you may cast it
for free, otherwise put it into your hand revealed.
Activate this ability as a sorcery.