Black Blade Of Disaster

You create a black blade-shaped planar rift about 3 feet
long. The blade strikes at any creature within its range, as you
desire, starting the round you cast the spell as a free action
once per turn. The blade makes a melee attack against its
designated target once each round using your spell attack
bonus.
Anything hit by the blade is disintegrated if it fails a
Constitution save, taking 10d10+70 points of force damage,
or half the damage if the saving throw is successful
The blade can pass through any magical barrier equal to or
less than its spell level, but cannot penetrate dead magic
arcas or an antimagic field It can harm ethercal and
incorporeal creatures as if it were a force effect.
The blade always strikes from your direction. It does not
get a flanking bonus or help a combatant get one. If the blade
exceeds its range or goes out of your line of sight, the spell
ends.
The blade is immue to most forms of magic, however a
gate spell can be used to counterspell a black blade of
disaster. The blade cannot be harmed by physical attacks, but
a sphere of annihilation can affect it.