Sobeckis Pool

Sobeckis Pool enters the battlefield tapped unless
you control a Sobecki permanent.
{t}: Add {b} or {g} to your mana pool.
{4}{b/g}{t}: Reveal cards from the top of your library
until you reveal a Sobecki permanent.
Put that card onto the battlefield and the rest
on the bottom of your library in any order.
"You can always find at least one of them there."