A J/resonator is never considered to be "battling" until after blockers are declared. A J/resonator is considered "battling" after a blocker (or no blocker) is declared if one of the following conditions are met at any time during the battle:
- It is the attacking or blocking J/resonator.
- It is the attacked object and there is no blocking J/resonator.
However, if the blocking J/resonator is removed after the attacking J/resonator has dealt battle damage, the attacked J/resonator (if any) is not considered to be "battling".
If "Zero, Master of the Magic Saber" is the attacked object, and the attacking J/resonator has Pierce, Zero will take any battle damage that would be applied (if there is a blocking J/resonator), as it is not considered to be "battling" at that time.