Wind Release: Vacuum Wave

Wind Release: Vacuum Wave 
 Ninjutsu (Wind); 
Level:
B Rank (5)
Hand Seals:
Rat → Snake → Horse → Dog
Casting Time:
Full Round
Range:
Personal
Area:
90 foot Burst
Duration:
Instantaneous
Saving Throw
None; Fortitude partial
The user takes a deep breath and spins while exhaling, compressing the released air into a solitary blade of wind that covers a substantial area around the user, due to their circular motion. The resulting sharpened blast is large enough to slice through multiple targets located a significant distance from the user, causing grievous injuries to those hit.
Opponent takes 10d6 of Damage Directly upon the attacks activation with no way to avoid it. Enemies within the area of effect will experience a knockdown. A successful Fortitude Save allows the defender to resist the knockdown.