Monothema, Brood Monarch

Sliver creatures you control have devoid and "Sacrifice this creature: Add {c}."
Whenever an ability of a colorless creature you
control would add an amount of {c}, add that
much mana in any combination of colors instead.
{w}{u}{b}{r}{g}: Search your library for a
nonlegendary Sliver or Eldrazi creature card and
put it onto the battlefield tapped, then shuffle.