Delver of Lairs

When Delver of Lairs enters the battlefield, if
you control a Lair, search your library for a
legendary Dragon creature card that shares a
color with the colors of mana a Lair you control
could produce, reveal it, and put it into your
hand. Then shuffle your library.
{1}{r}{g}, {t}, Sacrifice Delver of Lairs: Put a
legendary Dragon creature card from your hand
onto the battlefield. That creature gains haste.
Return it to your hand at the beginning of the
next end step.