Sky Striker Ace, Temperance

While you're searching your library, you may
cast Temperance from your library.
When Temperance enters the battlefield, gain
control of target permanent. Target permanent
becomes a land with: "{t}: Add one mana of any
color" and loses all other card types and abilities.
When Temperance dies or is put into exile from
the battlefield, you may shuffle it into
its owner's library.