Danica, Mistress of Flame

When Danica, Mistress of Flame enters the
battlefield, you may search your library for
up to two basic land cards. If you do, reveal
them, put them in your hand, and shuffle
your library.
{x}: Target opponent mills X cards, where X
is the number of elves you control.
Banished from her home unjustly, she saw to
it that those who wronged her burned for it.