The Tree of Life and Death

Whenever a source you control causes you to gain life, The Tree of Life and Death gains "{t}: Add {w} to your mana pool". Then, if The Tree of Life and Death has "{t}: Add {b} to your mana pool", it loses that ability.
Whenever a source you control causes you to lose life, The Tree of Life and Death gains "{t}: Add {b} to your mana pool". Then, if The Tree of Life and Death has "{t}: Add {w} to your mana pool", it loses that ability.