Mask of Darkness

When Mask of Darkness enters the battlefield
look at the top five cards of your library. You
may reveal a trap card from amongst them. If you
do, add it to your hand. Then put the rest on the bottom of your library in any order.
{2}, Exile Mask of Darkness from your hand:
Target land gains "{t}: Add {b}, {r}, or {w}" until
Mask of Darkness is cast from exile. You may
cast Mask of Darkness for as long as it remains
exiled.