Silumgar Broodmage

Channel- {u}{b}, Discard Silumgar Broodmage:
Add {u} or {b} to your mana pool for each land
you control that is a Swamp or Island.
{t}, Sacrifice Silumgar Broodmage: Add {u} to
your mana pool for each Swamp you control.
{t}, Sacrifice Silumgar Broodmage: Add {b} to
your mana pool for each Island you control.