Enchantment
When
this
enchantment
enters,
if
you
cast
it,
destroy
all
nonenchantment
creatures.
Whenever
this
enchantment
or
another
enchantment
you
control
enters,
until
end
of
turn,
this
enchantment
becomes
a
legendary
6/6
Nightmare
God
creature
with
menace
and
deathtouch.
It's
still
an
enchantment.