Castle Valencort, Heroes' Hold

Castle Valencort, Heroes' Hold enters the battlefield tapped unless you reveal a legendary creature or planeswalker card from your hand.
{t}: Add {w}, {r}, or {g}.
{2}, {t}: Add {w}{r}{g}. When you cast your next creature spell this turn, reveal the top card of
your library. If it's legendary, put it into your
hand. Otherwise, you may put it on the bottom
of your library.