Marth Tech: Z-Powershield
Description / How To Perform
Using a Z-Powershield greatly increases the frame window and distance at which you can powershield attacks compared to regular 
Powershields. A Z-Powershield is done by
pressing L/R and Z on the same frame, while already holding A.
Difficulty: 
(Expert)
Usefulness: (Generally Useful)
Extra Info
The requirement of having A held before being able to Z-Powershield is certainly a downfall, but if you press and hold A shortly after dashing you can avoid dash attacking. This can be used as a safe method of pressing the A button without triggering an attack.