Soul Departure

Until your next turn, your life total can't change
and you have protection from everything. All
permanents you control phase out. (While
they're phased out, they're treated as though they
don't exist. They phase in before you untap
during your untap step.)

At the beginning of your next turn's upkeep,
you lose the game unless you pay life equal to
half of your starting life total, rounded up.