Knowhere, Underworld Market

{t} Pay 1 life : Add {b} or {r}.
{t}: Add one mana of any color. Activate this
ability only if you control a creature with a +1/+1 counter on it.
{b/r}{b/r}{b/r}{t} Sacrifice Knowhere: Put a +1/+1
counter on target creature and draw a card.