C.3.P.O.

Partner with R.2. D.2. (When this creature enters the battlefield, target player may put
R.2. D.2. into their hand from their library,
then shuffle.)
Lands you control have {t}: Add two mana
of any one color to your mana pool. As long
as you control both C.3.P.O. and R.2. D.2.