Sorcery
Exchange
control
of
two
target
creatures
you
don't
control.
Flashback
.
This
spell
costs
less
to
cast
this
way,
where
X
is
the
greatest
mana
value
of
a
commander
you
own
on
the
battlefield
or
in
the
command
zone.
(You
may
cast
this
card
from
your
graveyard
for
its
flashback
cost.
Then
exile
it.)
