Mjolnir, the Hammer of Thor

When Mjolnir, the Hammer of Thor enters the battlefield, it deals 3 damage to each creature and planeswalker you don't control.
{2}{r}{t}: Sacrifice Mjolnir, the Hammer of Thor, search your library, hand and graveyard for a card named Thor, Lord of Lightning and put it onto the battlefield, then shuffle your library.