Rowan's Final Decision

All creatures lose indestructible until end of turn.
If a creature would die this turn, exile it instead.
Until this spell resolves you may pay 3 life, if you
do, add 1 to the value of X.
Rowan's Final Decision deals X damage to each
White and Blue creature. Each player who has a
creature exiled by this spell may choose up to 1
target Forest to exile.
Each opponent loses 3 life for each creature
they own in exile.