Koradeth, Maelstrom-Infuser

When Korradeth or another creature enters the battlefield under your control, Scry 2.
The first spell you cast from your library
each turn has Cascade.
{x}{g}{r}{u}: Look at the top card of your library, if
it's a nonland card with converted mana cost {x} or less, you may cast it without paying its mana
cost.