She also voices 5-volt.

I like how every other new Warioware a new "Volt" character gets their own set of microgames. The main differences between 5, 18, and 9 Volt in Gold specifically seems to be how their respective game controls, with 5-Volt's games all using button presses, 18-Volt using gyro controls, and 9-Volts use the touch screen. We're also being introduced to "13-Amp" as someone 18-Volt has a rap battle with, so I guess we may be seeing a new set of "Amp" characters in future games to act as rivals to the "Volts."