Mach Tornado
Mach Tornado is the name of Meta Knight's neutral B attack. Only seen in a screenshot, it appears visually similar to the Mario Tornado/Dr. Tornado and Luigi Cyclone; however Meta Knight uses his sword rather than his fists like the Mario brothers. The tornado also appears to be significantly larger than the Mario Tornado, Dr. Tornado, and Luigi Cyclone. It appears to be based on a similar move from Kirby Super Star. In a video posted outside of the Dojo, we see mostly how this attack works. It appears to last for about 3 seconds, Meta Knight can move freely during this attack, though it is unconfirmed if attack works like Mario and Luigi's (In that you must rapidly press the B button to go into the air), or if it doesn't require rapidly pressing B.