Gadeen, Palace of Penance

{t}, Pay 2 life: Add {w} or {b} to your mana pool.
Whenever you pay life, put a Tithe counter on
Gadeen, Palace of Penance.
{t}, Remove seven Tithe counters from Gadeen,
Palace of Penance: Each opponent loses 2 life.
You gain life equal to the amount of life lost
this way. Activate this ability only once each
turn.