The No Armor spell removes the effect of any armour the targetted player is wearing for a period of time. The higher the level of spell, the longer the effect lasts.
When you buy the No Armor spell in the wish shop, you'll be granted with 4 casts. If you already bought it before you get 4 additional casts, and the spell will be in a higher level. You can buy this spell 2 times in the wish shop.
The spell can be cast on a single player per cast, and should be cast by saying the spell words and then the player name, with the option of putting a hyphen (-) in between.