The multiply increases the amount the completion gauge gain for wiping out units for that shot. So if you have max multiplier and hit about 8 guys at once you could clear the level almost instantly early on.
If you are controlling a duelist have the stance be set to idle and then use the regroup the second you engage the enemy to speed up the flow of battle and get everyone on the target at once.
Protip: On the last level there are scratches on the ground by the two levers. Use them as guidelines along with one of your legs to get perfectly consistant timing on the switches. I managed to get both switches hit at the same time with the same sound before I beat the level.
@rappper: You should study physical attacks. They directly increase your accuracy. The combat school is a good way to get physical attack and defenses which effect accuracy and dodging.
 "Jack the Fugitive"){kind=icon}
 "The Budget Invasion"){kind=icon}
 "Valthirian Arc"){kind=icon}
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 "Kingdom of The Wind"){kind=icon}
 "BOWJA THE NINJA (on factory island)"){kind=icon}
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