Skybound Palace

As Skybound Palace enters the battlefield, you
may exile an enchantment or sorcery card from your graveyard. If you don't, Skybound Palace enters the battlefield tapped.
{t}: Add {w} or {u}.
During the reign of King Suleiman, the True Djinn
and the Djann collaborated in secret to build a palace
in the clouds where they need not fear enslavement.